Conceptual Physics 5

10. The primary source of electrons in an ordinary electrical circuit is

A. A dry cell, wet cell or battery. B. The back electromotive force of motors. C. The power station generator. D. The electrical circuit wire itself. E. None of these D

17. Pigeons navigate primarily by

A. A good memory B. A keen sense of smell C. Magnetic sensors in their heads D. Ultra-high-pitches in their heads E. None of these C

23. Rapid change of a magnetic field induces

A. A magnetic field of greater magnitude B. A magnetic field of the same magnitude C. An electrical field C

7. Which statement is correct?

A. A voltage difference is needed to make charge flow in a circuit. B. Voltage flows through an open or a closed circuit C. Resistance flows through an open circuit D. Current is the primary cause of voltage A

25. Positive and negative electric charges can occur independently; north and south magnetic poles

A. Also am an occur independently B. Must occur together C. Only occur in an electric field D. Are related to sound B

22. Power is transmitted at high voltages because the corresponding current in the wires is

A. Also high deliver appreciable power to distant places B. Low so that overheating of the wires is minimized C. Choices A and B are both true D. Choices A and B are both false B

16. Magnet A has twice the magnetic field strength of Magnet B and at a certain distance pulls in Magnet B with a force of 100 N. The amount of force the Magnet B exerts in Magnet A is

A. At or about 50 N B. Exactly 100 N C. More information is needed. D. 200 N B

14. Like minds of magnetic poles repel while unlike kinds of magnetic poles

A. Attract B. Repel C. May attract or repel D. Are always different colors A

18. When a bar magnet is thrust into a coil of copper wire, the coil tends to

A. Attract the magnet as it enters mob. B. Repel the magnet as it enters C. Both of these D. Neither of these B

3. The electrical force between charges is strongest when the charges are

A. Close together B. Far apart C. The electric force is constant everywhere A

19. Electromagnetic induction occurs in a coil when there is a change in

A. Electric field intensity in the coil B. Magnetic field intensity in the coil C. Voltage in the coil D. The coil's polarity E. Electromagnetic polarity B

1. In an electrically neutral atom the number of protons in the nucleus is equal to the number of

A. Electrons that surround the nucleus B. Neutrons in the nucleus C. Choices A and B both correct D. Choices A and B both in correct A

15. Magnetic field lines around a current -carrying wire

A. Extend radially from the wire B. Circle the wire in closed loops C. Choices A and B are both correct D. None of the above choices are correct B

20. A device that transforms electrical energy into mechanical energy is a

A. Generator B. Motor C. Transformer D. Magnet E. None of these B

8. The electrical resistance in a copper wire would be _______________ than that I'm a wooden cylinder of the same size.

A. Greater B. Less C. The same B

5. Superconductors are noted for their

A. High electric resistance B. Negative electric resistance C. Absence of electric resistance D. Low cost E. Bright colors C

9. In a DC circuit, the electric current

A. Increases in time vis the inverse-square law. B. Changes magnitude and direction with time. C. Always goes in the same direction. D. Is non-existent E. None of these C

11. A circuit breaker serves the purpose of

A. Limiting the voltage in a circuit B. Filling up an electric box C. Preventing too much current from flowing in a circuit D. All of the above choices are correct E. None of the above choices are correct C

4. The electrical force between two positive charges depends only on the charges'

A. Magnitude B. Separation distance C. Magnitude and separation distance D. None of the above choices are correct C

2. To say that electric charge is conserved is to say that electric charge

A. May occur in an infinite variety of quantities B. Is a whole number multiple of the charge of one electron C. Will interact with neighboring electric charges D. Can be neither created nor destroyed E. Is sometimes negative D

13. If a steady magnetic field exerts a force on a straight wire with a current flowing in it, that force is directed

A. Opposite the motion of the electrons B. In the direction of the motion of the electrons C. At right angles to the wire C

6. An ampere is a unit of electrical

A. Pressure B. Current C. Resistance D. All of these E. None of these B

12. The source of all magnetism is

A. Time pieces of iron B. Tiny domains of aligned atoms C. Ferromagnetic materials D. Moving electric charge E. None of these D

26. The electric circuits in a house operate at 120 volts. This is

A. Too low to cause serious harm to an adult B. Too low to cause a fire C. Can be safely be handled by anyone D. Is just high end ought to cause harm to a small child E. Is more than enough to kill an adult E

24. In a parallel circuit of light bulbs if on light bulb goes out the others go out too

A. True B. False B

21. A transformer actually transforms

A. Voltage. B. Magnetic field lines. C. Generators into motors. D. Non-safe forms of energy to safe forms of energy. E. All of the above choices are correct A