2. B The magnetic properties of a material depend on its. A) shape B) atomic structure C) position D) magnetic poles

Size: px

Start display at page:

Download "2. B The magnetic properties of a material depend on its. A) shape B) atomic structure C) position D) magnetic poles"

Gregory Tate
7 years ago
Views:

1 ame: Magnetic Properties 1. B What happens if you break a magnet in half? A) One half will have a north pole only and one half will have a south pole only. B) Each half will be a new magnet, with both a north and a south pole. C) either half will be able to attract or repel. D) either half will have a pole. Magnetism. B The magnetic properties of a material depend on its. A) shape B) atomic structure C) position D) magnetic poles 3. A A magnet made from hard steel is most likely a(n). A) permanent magnet B) temporary magnet C) electromagnet D) lodestone 4. C A cluster of billions of atoms that all have magnetic fields lined up in the same way is known as a. A) magnetic field line B) magnetic pole C) magnetic domain D) permanent magnet 5. C Which of the following statements describes the interaction between magnetic poles? A) Like poles attract each other. B) Opposite poles repel each other. C) Like poles repel each other, and opposite poles attract each other. D) Like poles attract each other, and opposite poles repel each other. 6. C Which of the following statements is true about ferromagnetic materials? A) All ferromagnetic materials are permanent magnets. B) Ferromagnetic materials that are permanent magnets have domains that are randomly oriented. C) Ferromagnetic materials that are permanent magnets have domains that remain aligned for long periods of time. D) Ferromagnetic materials do not have domains and cannot be magnetized. 7. D How can a permanent magnet be demagnetized? A) Cut the magnet in half. C) Strike the magnet with a heavy blow. B) Heat the magnet up. D) both B and C 8. B If you cut the magnet shown below along the dotted lines, there will be south pole(s). A) one B) two C) four D) eight 9. B The atoms in a magnet are. A) arranged randomly B) lined up C) negatively charged D) positively charged 10. C The source of all magnetism is. A) moving electric charges C) tiny domains of aligned atoms B) ferromagnetic materials D) tiny pieces of iron 11. D An iron rod becomes magnetic when. A) positive charges line up on one side and negative charges on the other side B) positive ions gather at one end and negative ions at the other end C) its electrons stop moving and point in the same direction D) the net spins of its electrons point in the same direction 1. C Magnetism is produced by the motion of electrons as they. A) move around the nucleus C) both A and B B) spin on their axes D) none of these 13. B Magnetic domains are. A) regions that may or may not be magnetized C) clusters of atoms randomly aligned B) regions of atoms magnetically aligned D) blocks of material Over

2 14. C Which of the diagrams best describes the consequences of breaking one bar magnet at its midpoint? A) S C) S S B) S S D) 15. D The motions of cause the field around a permanent magnet. A) nucleons B) protons C) neutrons D) electrons 16. C The region around a magnet where the magnetic force is exerted is known as its. A) magnetic pole B) lodestone C) magnetic field D) magnetic domain 17. D Which statement describes magnetic field lines at the north pole and south pole of a bar magnet? A) Field lines begin near the magnet s south pole and extend toward its north pole. B) Field lines begin near both the magnet s north and south poles and meet in the middle. C) Field lines begin near the center of the magnet and extend toward the north and south poles. D) Field lines begin near the magnet s north pole and extend toward its south pole. 18. B A changing magnetic field creates. A) nothing B) an electric field C) a gravitational field D) another magnetic field TRUE or FALSE: If false, change the underlined word(s) to make the statement true. 19. TRUE When you bring the south ends of two magnets close together, they repel each other. temporarily 0. A paper clip magnetized by a bar magnet is permanently magnetized. 1. aligned The magnetic domains of a permanent magnet are arranged randomly.. north The south pole of a compass points to the geographic north pole. field 3. The magnetic domain is the area around a magnet where the force acts. 4. strongest The field of a magnet is weakest at its poles. 5. opposite Magnetic field lines curve out from one pole and return to the same pole. do not 6. Because of the magnetic field, magnets do have to touch to affect each other.

3 ame: Magnetic Force and Field Magnetism 1. A An electron is moving parallel to a 0.5-tesla magnetic field. The magnetic force acting on the electron is. A) 0 B) 1 C) 5 D) cannot be determined. B An electron enters a magnetic field as shown. The subsequent path of the electron is a. A) parabola B) spiral C) hyperbola D) circle 3. B A wire carrying a current of A is placed in a magnetic field of 0.1 T. The length of wire in the magnetic field is 0.3 m. The magnitude of the force on the wire is. A) B) 0.06 C) 0.15 D).0 4. A beam of electrons travels at m/s through a uniform magnetic field of T at right angles to the field. How strong is the force that acts on each electron? F = 1.9 x An alpha particle carrying a charge of 3. x C moves at 5.5 x 10 7 m/s at a right angle to a magnetic field. If the particle experiences a force of 1.5 x due to the magnetic field, what is the field s magnitude? B = 8.5 x 10-4 T 6. A wire 0.50 m long carrying a current of 8.0 A is at right angles to a 0.70 T magnetic field. How strong is the force acting on the wire? F =.8 Over

4 7. The magnetic force on a straight 0.15 m segment of wire carrying a current of 4.5 A is 1.0. What is the magnitude of the component of the magnetic field that is perpendicular to the wire? 10. A proton moves perpendicularly to a magnetic field that has a magnitude of 4.0 x 10 T. What is the speed of the particle if the magnitude of the magnetic force on it is.40 x 10 14? B = 1.5 T F = 3.57 x 10 6 m/s 8. An electron passes through a magnetic field at right angles to the field at a velocity of m/s. The strength of the magnetic field is 0.50 T. What is the magnitude of the force acting on the electron? F = 3. x How intense is the magnetic field that exerts a force of 0.6 on a wire carrying 4 A of current perpendicularly to the field, if the length of the wire in the field is 5 cm? B = 3 T 9. A straight wire that carries a 5.0 A current is in a uniform magnetic field oriented at right angles to the wire. When 0.10 m of the wire is in the field, the force on the wire is 0.0. What is the strength of the magnetic field? 1. A wasp accumulates 1.0 x 10-1 C of charge while flying perpendicular to Earth's magnetic field of 5.0 x 10-5 T. How fast is the wasp flying if the magnetic force acting on it is 6.0 x 10-16? F = 0.40 T F = 1 m/s

5 ame: Electromagnetism Magnetism 1. C For which two angles between the direction of motion of a wire and a magnetic field can a current be induced across the wire? A) 0 and 45 B) 0 and 90 C) 45 and 90 D) 45 and 180 A. As the speed of a conducting loop rotating in a magnetic field decreases, the magnitude of the induced current in the loop. A) decrease B) increase C) remain the same C 3. A wire 0.10 m long is pushed through a magnetic field of strength 4.0 /A m in a direction perpendicular to the field. If the speed of the wire is.0 m/s, what is the magnitude of the induced voltage across the ends of the wire? A) 0.0 V B).0 V C) 0.80 V D) 0.50 V 4. B The magnitude of the electric potential induced across the ends of a conductor moving in a magnetic field may be increased by of the conductor. A) increasing the diameter C) decreasing the resistance B) increasing the speed D) decreasing the length B 5. As the difference in potential across the terminals of a solenoid increases, its magnetic flux density. A) decreases B) increases C) remains the same 6. D The diagram shows a copper wire located between the poles of a magnet. Maximum electric potential will be induced in the wire when it is moved at a constant speed toward which point? A) A B) B C) C D) D Base your answers to questions 7 and 8 on the diagram below that represents a conductor is moved perpendicularly through magnetic field B. D 7. What is being induced in the conductor? A) potential difference C) power B) resistance D) current B 8. If the magnetic field strength is doubled, the electric potential across the ends of the conductor will. A) be quartered C) be halved B) double D) remain the same 9. B The diagram below shows an end view of a metal rod moving upward perpendicular to a uniform magnetic field of.0 x 10 teslas. The.0-meter long wire is moving at a constant speed of 3.0 m/s. What is the emf induced across the rod? A) V B) 0.1 V C) 1. V D) 6.0 V 10. A The diagram shows the cross section of a wire that is perpendicular to the page and a uniform magnetic field directed to the right. Toward which point should the wire be moved to induce the maximum electric potential? A) 1 C) 3 B) D) 4 Over

6 D 11. The diagram represents a rectangular loop of wire that is rotating about the axis. Side AB is 0.50 m long and moving at a speed of.0 m/s. The strength of the uniform magnetic field is 4.0 Wb/m. What is the maximum electric potential induced across side AB? A) 16 V C) 10. V B) 1 V D) 4.0 V 1. Fill in the information requested for each diagram below: a) b) primary coil 1 V 10 A primary coil 6 V 10 A Type of Transformer: step down fewer turns on secondary 4 V Voltage on Secondary Coil: Type of Transformer: step up 60 A Current on Secondary Coil: 13. A step-up transformer has a primary coil supplied 14. A straight wire, 0.0 m long, moves at a constant with an effective AC voltage of 90.0 V consisting speed of 7.0 m/s perpendicular to a magnetic field of 00. turns and a secondary coil that has of strength 8.0 x 10 T. What emf is induced in turns. the wire? a) What is the voltage in the secondary circuit? 1 V V 1 V = 1350 V = BLv V = 0.11 V b) The current in the secondary circuit is.00 A. What is the current in the primary circuit? 1 I I 1 I 1 = 30.0 A

1. 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