Physics Spring Experiment #8 1 Experiment #8, Magnetic Forces Using the Current Balance


 Nicholas Lawson
 2 years ago
 Views:
Transcription
1 Physics Spring Experiment #8 1 Experiment #8, Magnetic Forces Using the Current Balance 1 Purpose 1. To demonstrate and measure the magnetic forces between current carrying wires. 2. To verify the theoretical predictions of the force between parallel current carrying wires and to utilize this result to obtain a value for the magnetic permeability constant, μ 0. 2 Introduction Fig. (1) shows a current balance which consists of two parallel rods. One of the rods forms one side of a rectangular loop that is balanced on knife edges and the other stationary rod is mounted directly under one of the sides of the rectangular loop. The loop pivots freely on knife edges and is balanced by a counterweight mounted on the loop. The equilibrium position of the upper rod with respect to the lower rod is set by changing the position of the counterweight. A mirror, mounted on the loop, is used to reflect a beam of heliumneon laser light for accurately determining the position of the upper rod. A tiny tray is mounted on the upper rod for placing very small weights on it. Figure 1. The Current Balance. A DC power supply is connected to both rods so that they carry equal but oppositely directed currents which induce a repulsive force between them. This repulsive force causes the pivoting of the upper rod. Small weights placed on the upper rod (tray) disturb the equilibrium position which is restored by passing a current through the rods. The value of these small weights can be used to determine the permeability constant of free space μ 0 /4π. The following section explains three types of forces encountered in this experiment. 2.1 Magnetic and Gravitational Forces Magnetic force of repulsion (or attraction) on the top rod. Consider the current configuration shown in Fig. (2). Two parallel rods of length L, separated by a centertocenter distance R, carry equal currents I in opposite directions. If the rods are oriented parallel to the xdirection, the current passing through the lower rod produces a magnetic field B z in the zdirection at the position of the upper rod. This magnetic field interacts with the current in the upper rod and causes a repulsive force F y on the upper rod in the ydirection. This repulsive force pivots the rectangular loop about the knife edges. If the length L is large compared to their separation R, the magnitude of the repulsive force is given by: L 2 I Fy = ( )( )I = BLI; B = ( )( ) (1) 2π R 2π R 3/6/2012
2 2 Review the derivation of Eq. (1) in your textbook. Note: 1. The fact that the current in each rod is in opposite directions is the reason for the force on the upper rod to be repulsive, as indicated in Fig. (2a). If the current in each rod is in the same direction, the magnetic force will be attractive as indicated in Fig. (2b). 2. The current in the upper rod exerts an equal and opposite magnetic force (down) on the lower rod, in agreement with Newton's 3rd law of interaction, i.e., of action and reaction. Because the lower rod is fixed, it does not move under the application of this force. 3. The magnitude of the magnetic force is directly proportional to the length L of the upper rod and inversely proportional to their separation distance R. 4. As the force is proportional to the square of the current, reversing the direction of the current in both rods will not reverse the direction of the force, i.e., the force will not become attractive Magnetic force on the upper rod due to the presence of the earth's magnetic field. The earth's magnetic field B e will exert a force F e on a conducting rod of length L and carrying a current I. The x, y and z components of force F e are related to I, L and the x, y and z components of B e in the following way: F e,x = 0 F e,y = ±ILB e,z (2) F e,z = ±ILB e,y In derivation of the above equations, it is assumed that the xaxis of the rectangular coordinate system is oriented in the direction of the current flow in the top rod and the yaxis is along the vertical. See Fig. (3).
3 Physics Spring Experiment #8 3 Figure 3: Magnetic force due to earth s magnetic field. Please note: 1. The ycomponent of the force F e,y can only pivot the loop while the zcomponent of force F e,z can only translate the loop. Thus, only the ycomponent of the force is responsible for the pivoting of the loop. 2. When the direction of the current I is reversed, the direction of the force on the upper rod by the earth's magnetic field reverses. This is in contrast to no change in the direction of the (repulsive) magnetic force on the upper rod due to the current in the lower rod. See section Gravitational force When small weights are placed in the tray on the upper rod, the gravitational force W acts on the upper rod in the vertically down direction. The force W in term of the weight's mass m is given by: 2.2 Net force on the upper rod of the current balance. F y = W = mg (3) The three forces discussed in Sections 2.1.1, and act simultaneously on the upper rod in ydirection and cause it to pivot. The net force on the rod is obtained by adding these three forces given by Eqs. (1), (2) and (3). Thus, the net force that causes the pivoting of the upper rod is given by: F net,y = μ 2π L R o 2 ( )( )I ± ILB e,z W (4) 2.3 Current balance operation With no weights added and no current in the rod, the equilibrium position of the current balance is noted by marking the spot made by the beam of light from a laser on a screen. When a known weight is added to the tray the light spot on the screen will shift down to a new position. The current I 1 through the rods is then increased until the light spot is restored to its equilibrium position. When this happens, the net force on the upper rod is zero. Applying the condition, F net,y = 0, to Eq. (4), one obtains the first of the two balancing equations: L 2 W = ( )( )I1 + I 1 LB e,z (5) 2π R 3/6/2012
4 If the direction (not the magnitude) of the current is reversed, there will be a shift in the position of the light spot. (This is so because the force due to the earth's magnetic field reverses its direction but other forces maintain their direction.) Thus, a current of different magnitude I 2 is needed to restore the light spot to its equilibrium position. When this is done, the net force on the upper rod is again zero. Thus, one obtains the second of the two balancing equations: L 2 W = ( )( )I2 I 2 LB e,z (6) 2π R Eqs. (5) and (6) can be rearranged to obtain the following two equations: 4 B e,z = ( ) 2πR (I 2  I 1 ) (7) L W = ( ) (I 1 I 2 ) (8) 2πR Eq. (7) is obtained by subtracting Eq. (6) from Eq. (5) and canceling the common factor (I 1 + I 2 ), and then rearranging the equation. Eq. (8) is obtained by first multiplying Eq. (5) by I 2 and Eq. (6) by I 1 and then adding them together, canceling the common factor (I 1 + I 2 ), and then rearranging the equation. Note that the currents I 1 and I 2 in the above equations are the magnitude of the forward and the reverse currents. Eqs. (7) and (8) are the working equations for this experiment. The experimental method consists of determining two balancing currents I 1 and I 2 for each weight W used. The data is then analyzed by plotting a graph of weights W (N) versus the product of balancing currents I 1 I 2 (A 2 ). According to Eq. (8), this graph should be a straight line whose intercept should be zero and whose slope S is given by: L Slope S = ( ) 2πR with units of A N 2 (9) Experimental Apparatus and Procedure 3.1 Apparatus 1. Welch Current Balance 2. Hampden variable DC power supply 3. Digital ammeter and voltmeter 4. DPDT switch (double pole/double throw) 5. Helium Neon Laser 6. Meter stick 7. A set of milligram standard masses 8. Rheostat and Various wires
5 The Welch current balance consists of a pivoted, rectangleshaped assembly of currentcarrying rectangular loop which pivots about the balance axis. One side of the loop is parallel to a fixed rod below it. See Fig. (1). With rods wired in series, the currents flowing in them will be in opposite directions and the upper rod will experience a repelling force which causes the balance to pivot upwards. See Fig. (2). Physics Spring Experiment #8 5 The orientation of the balance is monitored by the position of a laser beam reflected from a mirror attached to the balance frame [(Fig. (1)] to a screen placed several meters away from the balance [Fig. (4)]. When the balance rotates downward, the laser beam spot on the screen moves downward and vice versa. See Fig. (4) Figure 4: Beam of light reflected from a mirror. The current I to the rods is provided by a currentlimited DC power supply capable of providing up to 10 A of DC current. The current is measured using a batteryoperated digital multimeter set to measure current. The direction of current flow can be reversed by means of a doublepole/doublethrow (DPDT) switch. For safety's sake, the power supply should always be returned to zero before reversing the switch and the switch handled with one hand only. The electric circuit schematic for the experiment is shown in Fig Procedure Figure 5: Electric circuit. Warning: The current balance is a delicate instrument and needs to be treated with care. The teaching lab technician assembles the electric circuit and sets the experimental apparatus, so you most likely will not have to make any adjustment. Be sure not to disturb the balance by leaning on or bumping the lab bench. Do not put your books on the lab bench on which the balance sits, instead, put your lab notebook and the lab handout on the lab bench on which the screen sits. Leaning on the table during the experiment may result in large experimental errors, requiring you to redo the experiment. This experiment utilizes a laser which is safe to use only if you do not look into it. Please under no circumstances look into the laser otherwise you may damage your eye Preliminary check of the apparatus. 1. Check your balance by eye to make sure that it is properly aligned, i.e., that the two currentcarrying rods are parallel (and horizontal) with a separation of a few millimeters. Check that the rectangular loop is sitting properly on the knife edges. If necessary, the balance may be realigned gently, as demonstrated by the instructor. 3/6/2012
6 2. Turn on the HeNe laser and observe the red light spot. Before proceeding any further, tape a sheet of white unlined paper to the screen placed on an adjacent lab bench 34 meters from the balance. Observe that the laser spot is an extended circle. 3. Turn on the Hampden DC power supply and the digital multimeter. Make sure that the digital multimeter is set to read current in the 010 A range. Close the DPDT switch toward you. 4. Slowly turn the current control knob on the Hampden DC power supply up and down. As you do this, you should observe: a. The digital current meter indicates forward (+) current I 1. b. The balance pivots upward, indicating that the force on the top rod is repulsive. c. The light spot on the screen moves upward. 5. Turn down the current control knob to the zero position and observe the light spot return to its equilibrium position. Switch the DPDT away from you, to its reverse position. 6. Repeat Step 4, i.e., slowly turn the current control knob on the Hampden DC power supply up and down. As you do this, you should again observe: a. The digital current meter indicates reverse current I 2 with a negative sign. b. The balance pivots upward (not downward) indicating that the force on the upper rod is repulsive. c. The light spot on the screen moves upward. 7. Turn down the current control knob to the zero position and observe the light spot return to its equilibrium position. Switch the DPDT to its center offposition Measurements of currents I 1 and I 2 as a function of weight W placed on the upper rod. 1. Use the 6column data table. 2. With the DPDT switch in its center offposition mark the equilibrium position of the light spot, i.e., carefully draw a pencil line around the spot and darken it. Also mark the vertical position of the top of the light spot with one horizontal lines. Check that the spot returns to your marked position by turning the power to the circuit slowly up and down a few times. From now on, the equilibrium position of the current balance refers to this marked position of the light spot. 3. a. Gently place the 10 milligram mass on the tray using the tweezers. The current balance will pivot down and the light spot will move vertically down from the equilibrium position. b. Rebalance the current balance by increasing the current from zero (in the arbitrarily designated "forward" position of the DPDT switch) until the laser spot has risen back to the equilibrium position. Record the forward balancing current I 1. c. Turn the current back to zero. Reverse the DPDT switch, thus reversing the direction of current flow in both rods. Rebalance the current balance by increasing the current until the light spot returns to the equilibrium position. Record the "reversed" balancing current I 2. Note that the digital ammeter indicates a negative sign before the displayed digits. 4. Gently add another 10 milligram mass to the tray, making the total mass on the tray to be 20 milligrams. Repeat Step 3. 6
7 Physics Spring Experiment # Repeat Step 3 when the total mass on the tray is 30, 40, 50, 60, 70, 80, 90, and 100 milligrams. Caution: Once a weight is placed in the tray, do not remove any weights between steps in order to avoid jarring the current balance. 6. Turn off the Hampden power supply. Do not remove the weights. 7. Add the 1g weight. Observe that the upper rod touches the lower rod. Carefully draw a horizontal pencil line across the top edge of the light spot on the screen. Measure and record the distance y between the top and bottom horizontal line of the marks corresponding to the equilibrium and the 'clamped' positions of the light spot. 8. Additional Measurements: Make the following measurements necessary to obtain the value of the separation distance R between the upper and the lower rod as well as the value of the length L of the upper rod. Use a metric ruler to make these measurements. a. Measure the distance X from the pivot axis to the screen [Fig. (6)]. b. Measure the distance x from the pivot axis to the center of the upper rod. (Manufacturer's suggested value of x is cm.) c. For the measurement of the diameter and the length of the upper rod, do not disassemble your current balance. Use the disassembled current rod supplied in the lab. Measurement of L: Measure the distance between the center of two depressions on the disassembled rod. This distance is the length L of the currentcarrying rod. Note that the effective length L over which a magnetic force is present is between the two depressions in the rod where the current I enters and leaves the upper rod. The end segments of the rod outside these depressions do not carry current and therefore feel no magnetic force due to the current through the lower rod. (Manufacturer's nominal value is cm). Measurement of the diameter d: Measure the diameter, d, of the disassembled currentcarrying rod using a caliper (Manufacturer's nominal value is cm). 9. Carefully and very gently remove all the weights. The light spot should return to its equilibrium position; if not, you need to consult with the instructor. 4 Calculations and Analysis of the Data 1. Complete the remaining three columns in your data table, one each for W, I 1 I 2, and (I 2  I 1 ). Note: The absolute difference in the values of I 1 and I 2 is small and may show a considerable variation depending on how carefully you have done the experiment. In addition this difference will vary at different places in the lab depending upon the presence of magnetic material near your current balance. 2. Use your calculator to find the average value of (I 2  I 1 ). 3. Plot a graph of W versus I 1 I 2. This graph should be a linear graph. Calculate the slope on your graph. 4. Use linear regression to calculate the slope and the intercept of your linear data. 5. Calculate R using the following equation derived in Appendix A. 3/6/2012
8 yx R = d + ( ) (10) 2X Note: Your values of x, L and d should be close to those of the manufacturer. Use the manufacturer's value on page 7 if you are instructed to. 6. Calculate the permeability constant μ 0 /4π from your value of the slope S, R and L using the following equation derived from Eq. (9). Compare your value with the handbook value of μ 0 /4π = 1x107 N/A 2. 8 ( ) 4π R = ( ) S (11) 2 L (Note that μ 0 /2π = 2x107 N/A 2. This may help you with some of the calculations.) 7. Calculate the local magnetic field B e using Eq. 7 which is restated below. 5 Questions B e,z = ( ) 2πR (I 2  I 1 ) (12) 1. Derive Eqs. (7) and (8) from Eqs. (5) and (6). (Hints on page 4.) 2. How does your value of the permeability constant compare with its accepted value of μ 0 /4π = 1x107 N/A 2.? Calculate percent difference for this comparison. 3. Use equation 3 to calculate the magnitude of the repulsive magnetic force needed in your experiment to return the top rod to equilibrium when a mass of 80 mg was present on the tray. 4. Neglecting the effect of the earth=s magnetic field calculate the value of the current I needed to return the top rod to equilibrium when a mass of 80 mg was present on the upper rod. Use the force from question 3. Once calculated, use this current to calculate the value of the magnetic field B at the center of the rod. (Hint: Use equation 1 for both calculations and assume the current is constant in both directions.) 5. Compare your answer for the current I in question 4 to the average value of I 1 and I 2 for the mass of 80 mg (consult your data table). 6. Experimental Claims Questions. (a) (b) What can you claim to be true as a consequence of this experiment? What are the limitations on your claims as a result of the errors in your measurements? 7. Work Time Questions. (a) (b) How many hours did this report take to write? How many hours outside of class did you spend on this course this week? 6 Conclusion This section should have a clear statement of the results of the experiment and the extent to which the results are in agreement with the theory being tested. When the experiment results in a measurement of a constant, e.g., the acceleration of gravity, g, compare it with its established handbook values. Use percent difference for this comparison.
9 Physics Spring Experiment #8 9 To make this comparison meaningful, you should include the impact of the experimental error on your results. This includes errors in plotting and reading linear graphs when determining their slope and intercept. In addition, please include a statement of what you have learned, a critique of the experiment, and any suggestions you have which you think could improve the experiment or the lab handout. Appendix A Derivation of Equation (10): Figure A1 indicates two positions of the upper rod; one position when the upper rod is at its equilibrium position and the other when the upper rod is touching the lower rod. Figure 1A: Indicating the relationship between the defection of the upper rod and the reflected laser beam. When the upper rod moves from its equilibrium position to the position when it touches the lower rod, the displacement of the upper rod is given by ( R d ) where R is the center to center separation of the upper rod with respect to the lower rod and d is the diameter of each rod. When the upper rod touches the lower rod, it pivots by an angle α and the laser beam reflected from the mirror deflects by an angle δ. When the angle α is small, it is related to (R d) and x by: R  d α = ( ) (13) x Similarly, the angle δ is related to the deflection y of the laser beam on the screen placed a distance X from the pivot point in the following way: y δ = ( ) (14) X It is the simple matter to show that the angle δ is twice the angle α, i.e.,: Inserting Eqs. (14) and (15) in (16) and then by rearranging, one obtains: δ = 2 α (15) yx R = d + ( ) 2X (16) 3/6/2012
10 10 Appendix B Data Sheet Caution: Please follow the procedure in the lab handout. Mass * I 1 I 2 # (I )# # I 1 x I 2 # Weight * kg A A A A 2 N + Forward  Reverse x x x x x x x x x x * 1 milligram = 106 kg; W = mg, g = m/s 2 Additional Data: 1. Displacement of the laser light spot between equilibrium and clamped position of the current balance: y = cm 2. Distance from the pivot axis to the screen: X = cm 3. Distance from the pivot axis to the center of the upper rod: x = cm 4. Length of the current carrying rod: L = cm 5. Diameter of the upper rod: d = cm
Experiment #9, Magnetic Forces Using the Current Balance
Physics 182  Fall 2014  Experiment #9 1 Experiment #9, Magnetic Forces Using the Current Balance 1 Purpose 1. To demonstrate and measure the magnetic forces between current carrying wires. 2. To verify
More informationPrelab Quiz/PHYS 224 Magnetic Force and Current Balance. Your name Lab section
Prelab Quiz/PHYS 224 Magnetic Force and Current Balance Your name Lab section 1. What do you investigate in this lab? 2. Two straight wires are in parallel and carry electric currents in opposite directions
More informationPhysics 41, Winter 1998 Lab 1  The Current Balance. Theory
Physics 41, Winter 1998 Lab 1  The Current Balance Theory Consider a point at a perpendicular distance d from a long straight wire carrying a current I as shown in figure 1. If the wire is very long compared
More informationPHYS2212 LAB Coulomb s Law and the Force between Charged Plates
PHYS2212 LAB Coulomb s Law and the Force between Charged Plates Objectives To investigate the electrostatic force between charged metal plates and determine the electric permittivity of free space, ε
More informationPhysics 221 Experiment 5: Magnetic Fields
Physics 221 Experiment 5: Magnetic Fields August 25, 2007 ntroduction This experiment will examine the properties of magnetic fields. Magnetic fields can be created in a variety of ways, and are also found
More informationChapter 5. Magnetic Fields and Forces. 5.1 Introduction
Chapter 5 Magnetic Fields and Forces Helmholtz coils and a gaussmeter, two of the pieces of equipment that you will use in this experiment. 5.1 Introduction Just as stationary electric charges produce
More informationSTANDING WAVES. Objective: To verify the relationship between wave velocity, wavelength, and frequency of a transverse wave.
STANDING WAVES Objective: To verify the relationship between wave velocity, wavelength, and frequency of a transverse wave. Apparatus: Magnetic oscillator, string, mass hanger and assorted masses, pulley,
More informationF B = ilbsin(f), L x B because we take current i to be a positive quantity. The force FB. L and. B as shown in the Figure below.
PHYSICS 176 UNIVERSITY PHYSICS LAB II Experiment 9 Magnetic Force on a Current Carrying Wire Equipment: Supplies: Unit. Electronic balance, Power supply, Ammeter, Lab stand Current Loop PC Boards, Magnet
More informationPrelab Exercises: Hooke's Law and the Behavior of Springs
59 Prelab Exercises: Hooke's Law and the Behavior of Springs Study the description of the experiment that follows and answer the following questions.. (3 marks) Explain why a mass suspended vertically
More informationMagnetism. d. gives the direction of the force on a charge moving in a magnetic field. b. results in negative charges moving. clockwise.
Magnetism 1. An electron which moves with a speed of 3.0 10 4 m/s parallel to a uniform magnetic field of 0.40 T experiences a force of what magnitude? (e = 1.6 10 19 C) a. 4.8 10 14 N c. 2.2 10 24 N b.
More informationTIME OF COMPLETION DEPARTMENT OF NATURAL SCIENCES. PHYS 2212, Exam 2 Section 1 Version 1 April 16, 2014 Total Weight: 100 points
TIME OF COMPLETION NAME DEPARTMENT OF NATURAL SCIENCES PHYS 2212, Exam 2 Section 1 Version 1 April 16, 2014 Total Weight: 100 points 1. Check your examination for completeness prior to starting. There
More informationFORCE ON A CURRENT IN A MAGNETIC FIELD
7/16 Force current 1/8 FORCE ON A CURRENT IN A MAGNETIC FIELD PURPOSE: To study the force exerted on an electric current by a magnetic field. BACKGROUND: When an electric charge moves with a velocity v
More informationA Determination of g, the Acceleration Due to Gravity, from Newton's Laws of Motion
A Determination of g, the Acceleration Due to Gravity, from Newton's Laws of Motion Objective In the experiment you will determine the cart acceleration, a, and the friction force, f, experimentally for
More informationExperiment #8: Magnetic Forces
Experiment #8: Magnetic Forces Purpose: To study the nature of magnetic forces exerted on currents. Equipment: Magnet Assembly and Stand Set of Current Loop PC oards TripleArm Pan alance 0 15 V dc Variable
More information1. The diagram below represents magnetic lines of force within a region of space.
1. The diagram below represents magnetic lines of force within a region of space. 4. In which diagram below is the magnetic flux density at point P greatest? (1) (3) (2) (4) The magnetic field is strongest
More informationLab: Vectors. You are required to finish this section before coming to the lab. It will be checked by one of the lab instructors when the lab begins.
Lab: Vectors Lab Section (circle): Day: Monday Tuesday Time: 8:00 9:30 1:10 2:40 Name Partners PreLab You are required to finish this section before coming to the lab. It will be checked by one of the
More informationTHE SPRING CONSTANT. Apparatus: A spiral spring, a set of weights, a weight hanger, a balance, a stop watch, and a twometer
THE SPRING CONSTANT Objective: To determine the spring constant of a spiral spring by Hooe s law and by its period of oscillatory motion in response to a weight. Apparatus: A spiral spring, a set of weights,
More informationMagnetic Force on a CurrentCarrying Wire
Title: Original Version: Revision: Authors: Appropriate Level: Abstract: Time Required: NY Standards Met: AP Physics Learning Objective: Magnetic Force on a CurrentCarrying Wire 11 November 2006 24 June
More informationMagnetism Conceptual Questions. Name: Class: Date:
Name: Class: Date: Magnetism 22.1 Conceptual Questions 1) A proton, moving north, enters a magnetic field. Because of this field, the proton curves downward. We may conclude that the magnetic field must
More informationExperiment 7: Forces and Torques on Magnetic Dipoles
MASSACHUSETTS INSTITUTE OF TECHNOLOY Department of Physics 8. Spring 5 OBJECTIVES Experiment 7: Forces and Torques on Magnetic Dipoles 1. To measure the magnetic fields due to a pair of currentcarrying
More informationLab 8: Ballistic Pendulum
Lab 8: Ballistic Pendulum Equipment: Ballistic pendulum apparatus, 2 meter ruler, 30 cm ruler, blank paper, carbon paper, masking tape, scale. Caution In this experiment a steel ball is projected horizontally
More informationGeneral Physics Lab: Atwood s Machine
General Physics Lab: Atwood s Machine Introduction One may study Newton s second law using a device known as Atwood s machine, shown below. It consists of a pulley and two hanging masses. The difference
More informationPhysics 1020 Laboratory #6 Equilibrium of a Rigid Body. Equilibrium of a Rigid Body
Equilibrium of a Rigid Body Contents I. Introduction II. III. IV. Finding the center of gravity of the meter stick Calibrating the force probe Investigation of the angled meter stick V. Investigation of
More informationUpdated 2013 (Mathematica Version) M1.1. Lab M1: The Simple Pendulum
Updated 2013 (Mathematica Version) M1.1 Introduction. Lab M1: The Simple Pendulum The simple pendulum is a favorite introductory exercise because Galileo's experiments on pendulums in the early 1600s are
More informationPhysics 126 Practice Exam #3 Professor Siegel
Physics 126 Practice Exam #3 Professor Siegel Name: Lab Day: 1. Which one of the following statements concerning the magnetic force on a charged particle in a magnetic field is true? A) The magnetic force
More informationLab M1: The Simple Pendulum
Lab M1: The Simple Pendulum Introduction. The simple pendulum is a favorite introductory exercise because Galileo's experiments on pendulums in the early 1600s are usually regarded as the beginning of
More informationPHY 212 LAB Magnetic Field As a Function of Current
PHY 212 LAB Magnetic Field As a Function of Current Apparatus DC Power Supply two D batteries one round bulb and socket a long wire 10Ω resistor set of alligator clilps coil Scotch tape function generator
More informationPhysics 6A Lab Experiment 6
Physics 6A Lab Experiment 6 Biceps Muscle Model APPARATUS Biceps model Large mass hanger with four 1kg masses Small mass hanger for hand end of forearm bar with five 100g masses Meter stick Centimeter
More informationEquilibrium. To determine the mass of unknown objects by utilizing the known force requirements of an equilibrium
Equilibrium Object To determine the mass of unknown objects by utilizing the known force requirements of an equilibrium situation. 2 Apparatus orce table, masses, mass pans, metal loop, pulleys, strings,
More informationEXPERIMENT IV. FORCE ON A MOVING CHARGE IN A MAGNETIC FIELD (e/m OF ELECTRON ) AND. FORCE ON A CURRENT CARRYING CONDUCTOR IN A MAGNETIC FIELD (µ o )
1 PRINCETON UNIVERSITY PHYSICS 104 LAB Physics Department Week #4 EXPERIMENT IV FORCE ON A MOVING CHARGE IN A MAGNETIC FIELD (e/m OF ELECTRON ) AND FORCE ON A CURRENT CARRYING CONDUCTOR IN A MAGNETIC FIELD
More informationAmpere's Law. Introduction. times the current enclosed in that loop: Ampere's Law states that the line integral of B and dl over a closed path is 0
1 Ampere's Law Purpose: To investigate Ampere's Law by measuring how magnetic field varies over a closed path; to examine how magnetic field depends upon current. Apparatus: Solenoid and path integral
More informationLab 9 Magnetic Interactions
Lab 9 Magnetic nteractions Physics 6 Lab What You Need To Know: The Physics Electricity and magnetism are intrinsically linked and not separate phenomena. Most of the electrical devices you will encounter
More informationSimple Harmonic Motion
Simple Harmonic Motion 9M Object: Apparatus: To determine the force constant of a spring and then study the harmonic motion of that spring when it is loaded with a mass m. Force sensor, motion sensor,
More information041. Newton s First Law Newton s first law states: Sections Covered in the Text: Chapters 4 and 8 F = ( F 1 ) 2 + ( F 2 ) 2.
Force and Motion Sections Covered in the Text: Chapters 4 and 8 Thus far we have studied some attributes of motion. But the cause of the motion, namely force, we have essentially ignored. It is true that
More informationInstruction Manual and Experiment Guide A. Tension Protractor ME6855
Instruction Manual and Experiment Guide 01210381A Tension Protractor ME6855 Table of Contents Introduction......................................................................... 1 About the Apparatus..................................................................
More informationCHARGE TO MASS RATIO OF THE ELECTRON
CHARGE TO MASS RATIO OF THE ELECTRON In solving many physics problems, it is necessary to use the value of one or more physical constants. Examples are the velocity of light, c, and mass of the electron,
More informationLab 5: Conservation of Energy
Lab 5: Conservation of Energy Equipment SWS, 1meter stick, 2meter stick, heavy duty bench clamp, 90cm rod, 40cm rod, 2 double clamps, brass spring, 100g mass, 500g mass with 5cm cardboard square
More informationCharged Particles Moving in an Magnetic Field
rev 12/2016 Charged Particles Moving in an Magnetic Field Equipment for Part 1 Qty Item Parts Number 1 Magnetic Field Sensor CI6520A 1 Zero Gauss Chamber EM8652 1 Dip Needle SF8619 1 Angle Indicator
More informationSIMPLE HARMONIC MOTION
SIMPLE HARMONIC MOTION PURPOSE The purpose of this experiment is to investigate one of the fundamental types of motion that exists in nature  simple harmonic motion. The importance of this kind of motion
More informationObtaining the speed of light using the Foucault Method
Obtaining the speed of light using the Foucault Method and the PASCO apparatus. Quintin T. Nethercott and M. Evelynn Walton University of Utah Department of Physics and Astronomy Advanced Undergraduate
More informationTHE CONSERVATION OF ENERGY  PENDULUM 
THE CONSERVATION OF ENERGY  PENDULUM  Introduction The purpose of this experiment is to measure the potential energy and the kinetic energy of a mechanical system and to quantitatively compare the two
More informationPhysics 2212 GH Quiz #4 Solutions Spring 2015
Physics 1 GH Quiz #4 Solutions Spring 15 Fundamental Charge e = 1.6 1 19 C Mass of an Electron m e = 9.19 1 31 kg Coulomb constant K = 8.988 1 9 N m /C Vacuum Permittivity ϵ = 8.854 1 1 C /N m Earth s
More informationMFF 3a: Charged Particle and a Straight CurrentCarrying Wire... 2
MFF 3a: Charged Particle and a Straight CurrentCarrying Wire... 2 MFF3a RT1: Charged Particle and a Straight CurrentCarrying Wire... 3 MFF3a RT2: Charged Particle and a Straight CurrentCarrying Wire...
More informationMagnetic Force on a CurrentCarrying Wire Warm Up
Magnet Force on Current1 Magnetic Force on a CurrentCarrying Wire Warm Up 1. Forces on magnets Assume that we have a magnet of mass m 1 sitting on a scale (force meter 1), situation A. For this configuration
More informationChapter 14: Magnets and Electromagnetism
Chapter 14: Magnets and Electromagnetism 1. Electrons flow around a circular wire loop in a horizontal plane, in a direction that is clockwise when viewed from above. This causes a magnetic field. Inside
More informationExperiment 6: Magnetic Force on a Current Carrying Wire
Chapter 8 Experiment 6: Magnetic Force on a Current Carrying Wire 8.1 Introduction Maricourt (1269) is credited with some of the original work in magnetism. He identified the magnetic force centers of
More informationLab 5  Electron ChargetoMass Ratio
Lab 5 Electron ChargetoMass Ratio L51 Name Date Partners Lab 5  Electron ChargetoMass Ratio OBJECTIVES To understand how electric and magnetic fields impact an electron beam To experimentally determine
More informationSimple Harmonic Motion
Simple Harmonic Motion 1 Object To determine the period of motion of objects that are executing simple harmonic motion and to check the theoretical prediction of such periods. 2 Apparatus Assorted weights
More informationLab 11: Magnetic Fields Name:
Lab 11: Magnetic Fields Name: Group Members: Date: TA s Name: Objectives: To measure and understand the magnetic field of a bar magnet. To measure and understand the magnetic field of an electromagnet,
More informationHMWK 3. Ch 23: P 17, 23, 26, 34, 52, 58, 59, 62, 64, 73 Ch 24: Q 17, 34; P 5, 17, 34, 42, 51, 52, 53, 57. Chapter 23
HMWK 3 Ch 23: P 7, 23, 26, 34, 52, 58, 59, 62, 64, 73 Ch 24: Q 7, 34; P 5, 7, 34, 42, 5, 52, 53, 57 Chapter 23 P23.7. Prepare: The connecting wires are ideal with zero resistance. We have to reduce the
More informationPhysics 6C, Summer 2006 Homework 1 Solutions F 4
Physics 6C, Summer 006 Homework 1 Solutions All problems are from the nd edition of Walker. Numerical values are different for each student. Chapter Conceptual Questions 18. Consider the four wires shown
More information11/27/2014 Partner: Diem Tran. Bungee Lab I: Exploring the Relationship Between Bungee Cord Length and Spring Force Constant
Bungee Lab I: Exploring the Relationship Between Bungee Cord Length and Spring Force Constant Introduction: This lab relies on an understanding of the motion of a spring and spring constant to facilitate
More informationAP Physics B Free Response Solutions
AP Physics B Free Response Solutions. (0 points) A sailboat at rest on a calm lake has its anchor dropped a distance of 4.0 m below the surface of the water. The anchor is suspended by a rope of negligible
More informationThe Big Idea. Key Concepts
The ig Idea For static electric charges, the electromagnetic force is manifested by the Coulomb electric force alone. If charges are moing, howeer, there is created an additional force, called magnetism.
More informationThe Charge to Mass Ratio (e/m) Ratio of the Electron. NOTE: You will make several sketches of magnetic fields during the lab.
The Charge to Mass Ratio (e/m) Ratio of the Electron NOTE: You will make several sketches of magnetic fields during the lab. Remember to include these sketches in your lab notebook as they will be part
More informationFRICTION, WORK, AND THE INCLINED PLANE
FRICTION, WORK, AND THE INCLINED PLANE Objective: To measure the coefficient of static and inetic friction between a bloc and an inclined plane and to examine the relationship between the plane s angle
More informationSolution: (a) For a positively charged particle, the direction of the force is that predicted by the right hand rule. These are:
Problem 1. (a) Find the direction of the force on a proton (a positively charged particle) moving through the magnetic fields as shown in the figure. (b) Repeat part (a), assuming the moving particle is
More informationForce. Net Force Mass. Acceleration = Section 1: Weight. Equipment Needed Qty Equipment Needed Qty Force Sensor 1 Mass and Hanger Set 1 Balance 1
Department of Physics and Geology Background orce Physical Science 1421 A force is a vector quantity capable of producing motion or a change in motion. In the SI unit system, the unit of force is the Newton
More informationFaraday's Law and Inductance
Page 1 of 8 test2labh_status.txt Use Internet Explorer for this laboratory. Save your work often. NADN ID: guest49 Section Number: guest All Team Members: Your Name: SP212 Lab: Faraday's Law and Inductance
More informationPhysics 112 Homework 5 (solutions) (2004 Fall) Solutions to Homework Questions 5
Solutions to Homework Questions 5 Chapt19, Problem2: (a) Find the direction of the force on a proton (a positively charged particle) moving through the magnetic fields in Figure P19.2, as shown. (b) Repeat
More informationDate: Deflection of an Electron in a Magnetic Field
Name: Partners: Date: Deflection of an Electron in a Magnetic Field Purpose In this lab, we use a Cathode Ray Tube (CRT) to measure the effects of an electric and magnetic field on the motion of a charged
More informationMagnets and the Magnetic Force
Magnets and the Magnetic Force We are generally more familiar with magnetic forces than with electrostatic forces. Like the gravitational force and the electrostatic force, this force acts even when the
More informationTHE MAGNETIC FIELD. 9. Magnetism 1
THE MAGNETIC FIELD Magnets always have two poles: north and south Opposite poles attract, like poles repel If a bar magnet is suspended from a string so that it is free to rotate in the horizontal plane,
More informationAddition and Resolution of Vectors Equilibrium of a Particle
Overview Addition and Resolution of Vectors Equilibrium of a Particle When a set of forces act on an object in such a way that the lines of action of the forces pass through a common point, the forces
More informationPHY 157 Standing Waves on a String (Experiment 5)
PHY 157 Standing Waves on a String (Experiment 5) Name: 1 Introduction In this lab you will observe standing waves on a string. You will also investigate the relationship between wave speed and tension
More informationMeasurement of ChargetoMass (e/m) Ratio for the Electron
Measurement of ChargetoMass (e/m) Ratio for the Electron Experiment objectives: measure the ratio of the electron chargetomass ratio e/m by studying the electron trajectories in a uniform magnetic
More informationPhysics 121 Sample Common Exam 3 NOTE: ANSWERS ARE ON PAGE 6. Instructions: 1. In the formula F = qvxb:
Physics 121 Sample Common Exam 3 NOTE: ANSWERS ARE ON PAGE 6 Signature Name (Print): 4 Digit ID: Section: Instructions: Answer all questions 24 multiple choice questions. You may need to do some calculation.
More informationMagnetism. ***WARNING: Keep magnets away from computers and any computer disks!***
Magnetism This lab is a series of experiments investigating the properties of the magnetic field. First we will investigate the polarity of magnets and the shape of their field. Then we will explore the
More informationChapter 14 Magnets and
Chapter 14 Magnets and Electromagnetism How do magnets work? What is the Earth s magnetic field? Is the magnetic force similar to the electrostatic force? Magnets and the Magnetic Force! We are generally
More informationRotational Motion: Moment of Inertia
Experiment 8 Rotational Motion: Moment of Inertia 8.1 Objectives Familiarize yourself with the concept of moment of inertia, I, which plays the same role in the description of the rotation of a rigid body
More informationThe quest to find how x(t) and y(t) depend on t is greatly simplified by the following facts, first discovered by Galileo:
Team: Projectile Motion So far you have focused on motion in one dimension: x(t). In this lab, you will study motion in two dimensions: x(t), y(t). This 2D motion, called projectile motion, consists of
More informationExam 2 Solutions. PHY2054 Spring Prof. P. Kumar Prof. P. Avery March 5, 2008
Prof. P. Kumar Prof. P. Avery March 5, 008 Exam Solutions 1. Two cylindrical resistors are made of the same material and have the same resistance. The resistors, R 1 and R, have different radii, r 1 and
More informationLAB 6: GRAVITATIONAL AND PASSIVE FORCES
55 Name Date Partners LAB 6: GRAVITATIONAL AND PASSIVE FORCES And thus Nature will be very conformable to herself and very simple, performing all the great Motions of the heavenly Bodies by the attraction
More informationLesson 04: Newton s laws of motion
www.scimsacademy.com Lesson 04: Newton s laws of motion If you are not familiar with the basics of calculus and vectors, please read our freely available lessons on these topics, before reading this lesson.
More informationLABORATORY 9. Simple Harmonic Motion
LABORATORY 9 Simple Harmonic Motion Purpose In this experiment we will investigate two examples of simple harmonic motion: the massspring system and the simple pendulum. For the massspring system we
More informationMagnetic Field Lines. Uniform Magnetic Field. Earth s Magnetic Field 6/3/2013
Chapter 33: Magnetism Ferromagnetism Iron, cobalt, gadolinium strongly magnetic Can cut a magnet to produce more magnets (no magnetic monopole) Electric fields can magnetize nonmagnetic metals Heat and
More informationKirchhoff s Laws. Kirchhoff's Law #1  The sum of the currents entering a node must equal the sum of the currents exiting a node.
Kirchhoff s Laws There are two laws necessary for solving circuit problems. For simple circuits, you have been applying these equations almost instinctively. Kirchhoff's Law #1  The sum of the currents
More informationPC1221 Fundamentals of Physics I Inertia Wheel
PC1221 Fundamentals of Physics I Inertia Wheel 1 Purpose Determination of the angular acceleration of the inertial wheel as a function of the applied torque Determination of the moment of inertia I of
More informationmv = ev ebr Application: circular motion of moving ions In a uniform magnetic field: The mass spectrometer KE=PE magnitude of electron charge
1.4 The Mass Spectrometer Application: circular motion of moving ions In a uniform magnetic field: The mass spectrometer mv r qb mv eb magnitude of electron charge 1 mv ev KEPE v 1 mv ebr m v e r m B m
More informationExperimental Question 1: Levitation of Conductors in an Oscillating Magnetic Field SOLUTION ( )
a. Using Faraday s law: Experimental Question 1: Levitation of Conductors in an Oscillating Magnetic Field SOLUTION The overall sign will not be graded. For the current, we use the extensive hints in the
More informationLab 8: Buoyancy and Archimedes Principle
Description Lab 8: Buoyancy and Archimedes Principle In this lab, you will explore the force that displacing a fluid (liquid or gas) will exert on the body displacing the fluid. You will study how the
More informationLab 3  Projectile Motion Scientific Data Collection and Analysis (with some experimental design)
Partner 1: Lab 3  Scientific Data Collection and Analysis (with some experimental design) Purpose: This Minilab is designed help you apply the skills you learned in the homework; that is, to collect data
More informationStudy the effects of electric and magnetic fields on a charged particle and measure the chargetomass ratio (e/m) of the electron.
Experiment 2 The Ratio e/m for Electrons 2.1 Objective Study the effects of electric and magnetic fields on a charged particle and measure the chargetomass ratio (e/m) of the electron. 2.2 Theory In
More informationGoals. Introduction R = DV I (7.1)
Lab 7. Ohm s Law Goals To understand Ohm s law, used to describe the behavior of electrical conduction in many materials and circuits. To calculate the electrical power dissipated as heat in electrical
More informationPHY222 Lab 3 Ohm s Law and Electric Circuits Ohm s Law; Series Resistors; Circuits Inside Three and FourTerminal Black Boxes
PHY222 Lab 3 Ohm s Law and Electric Circuits Ohm s Law; Series Resistors; Circuits Inside Three and FourTerminal Black Boxes Print Your Name Print Your Partners' Names Instructions February 5, 2015 Before
More informationUnit III Current Balance
Unit III Current Balance Keywords: Lorentz force Ampers right hand rule Objective: Denmark scientist Hans Christian Oersted accidentally found that the currentcarrying wire would affect the pointing direction
More informationGENERAL SCIENCE LABORATORY 1110L Lab Experiment 5 THE SPRING CONSTANT
GENERAL SCIENCE LABORATORY 1110L Lab Experiment 5 THE SPRING CONSTANT Objective: To determine the spring constant of a spiral spring Apparatus: Pendulum clamp, aluminum pole, large clamp, assorted masses,
More informationPhysics 1051 Laboratory #6 Diffraction. CD Diffraction
CD Diffraction Contents Part I: Setup Part II: The Diffraction Grating Part III: CD Groove Spacing Part I: Introduction One of the goals in this lab is to use a diffraction grating to determine the wavelength
More informationSimple Harmonic Motion Concepts
Simple Harmonic Motion Concepts INTRODUCTION Have you ever wondered why a grandfather clock keeps accurate time? The motion of the pendulum is a particular kind of repetitive or periodic motion called
More informationPearson Physics Level 30 Unit VI Forces and Fields: Chapter 12 Solutions
Concept Check (top) Pearson Physics Level 30 Unit VI Forces and Fields: Chapter 1 Solutions Student Book page 583 Concept Check (bottom) The northseeking needle of a compass is attracted to what is called
More informationExperiment 9: Biot Savart Law with Helmholtz Coil
Experiment 9: Biot Savart Law with Helmholtz Coil ntroduction n this lab we will study the magnetic fields of circular current loops using the BiotSavart law. The BiotSavart Law states the magnetic
More informationEXPERIMENT 7 OHM S LAW, RESISTORS IN SERIES AND PARALLEL
260 7 I. THEOY EXPEIMENT 7 OHM S LAW, ESISTOS IN SEIES AND PAALLEL The purposes of this experiment are to test Ohm's Law, to study resistors in series and parallel, and to learn the correct use of ammeters
More informationExperiment P007: Acceleration due to Gravity (Free Fall Adapter)
Experiment P007: Acceleration due to Gravity (Free Fall Adapter) EQUIPMENT NEEDED Science Workshop Interface Clamp, right angle Base and support rod Free fall adapter Balls, 13 mm and 19 mm Meter stick
More informationMagnetic Fields; Sources of Magnetic Field
This test covers magnetic fields, magnetic forces on charged particles and currentcarrying wires, the Hall effect, the BiotSavart Law, Ampère s Law, and the magnetic fields of currentcarrying loops
More informationPHYSICS 176 UNIVERSITY PHYSICS LAB II. Experiment 2 (two weeks) Direct Current Measurement and Ohm's Law
PHYSICS 176 UNIVERSITY PHYSICS LAB II Experiment 2 (two weeks) Direct Current Measurement and Ohm's Law Equipment: Supplies: VOM (voltohmmilliammeter), digital multimeter, power supply. 1/2 watt carbon
More informationResistors in Series and Parallel
Resistors in Series and Parallel INTRODUCTION Direct current (DC) circuits are characterized by the quantities current, voltage and resistance. Current is the rate of flow of charge. The SI unit is the
More information6/2016 E&M forces1/8 ELECTRIC AND MAGNETIC FORCES. PURPOSE: To study the deflection of a beam of electrons by electric and magnetic fields.
6/016 E&M forces1/8 ELECTRIC AND MAGNETIC FORCES PURPOSE: To study the deflection of a beam of electrons by electric and magnetic fields. APPARATUS: Electron beam tube, stand with coils, power supply,
More informationConcept Review. Physics 1
Concept Review Physics 1 Speed and Velocity Speed is a measure of how much distance is covered divided by the time it takes. Sometimes it is referred to as the rate of motion. Common units for speed or
More informationPhysics 1653 Exam 3  Review Questions
Physics 1653 Exam 3  Review Questions 3.0 Two uncharged conducting spheres, A and B, are suspended from insulating threads so that they touch each other. While a negatively charged rod is held near, but
More informationPHY222 Lab 7  Magnetic Fields and Right Hand Rules Magnetic forces on wires, electron beams, coils; direction of magnetic field in a coil
PHY222 Lab 7  Magnetic Fields and Right Hand Rules Magnetic forces on wires, electron beams, coils; direction of magnetic field in a coil Print Your Name Print Your Partners' Names You will return this
More information