MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.Course sort 15275 ID AA 04

1) Like kinds of magnetic poles repel while unlike kinds of magnetic poles A) attract. B) repel also. C) may attract or repel.

1. An electric motor and electric generator are: A) very similar devices. B) entirely different devices.
2. Two protons attract each other gravitationally and repel each other electrically. By far the greater is: A) the gravitational attraction. B) the electrical repulsion. C) neither - they are the same.
3. If a steady magnetic field exerts a force on a moving charge, that force is directed:
A) in the direction of the field. B) opposite the direction of the field. C) at right angles to the direction of the field.
4. The frequency of a note one octave higher in pitch than a 440-Hz note is: A) 1760 Hz. B) 880 Hz. C) 440 Hz. D) 220 Hz. E) 110 Hz.
5. Double the frequency of a sound and you halve its: A) wavelength. B) speed. C) amplitude. D) all of these.
E) none of these.
6. Compared to the primary voltage, the secondary voltage may be: A) larger. B) smaller. C) the same.
D) the same or smaller, but not larger. E) larger, smaller, or the same.
7. The source of electrons in an ordinary electrical circuit is: A) a dry cell, wet cell or battery. B) the back emf of motors. C) the power station generator. D) the electrical conductor itself. E) none of these.
8. On some early automobiles both headlights went out when one bulb burned out. The headlights must have been connected in: A) parallel. B) perpendicular. C) series. D) haste.
9. The vibrations of a transverse wave move in a direction: A) along the direction of wave travel. B) at right angles to the direction of wave travel.
10. The electrical force between charges depends on the: A) magnitude of electric charges. B) separation distance between electric charges. C) both of these. D) none of these.
11. Magnetism is due to the motion of electrons as they : A) move around the nucleus. B) spin on their axes.
C) both of these. D) none of these.
12. Sound travels faster in : A) air. B) water. C) steel. D) a vacuum. E) sound travels at about the same speed in all of these.
13. A conductor differs from an insulator in that a conductor: A) has more electrons than protons. B) has more protons than electrons. C) has more energy than an insulator. D) has faster moving molecules. E) none of these.
14. Metal detectors, like the ones used at airports, are activated by: A) electric fields. B) magnetic fields.
C) electromagnetic induction. D) alternating current.
15. Outside a magnet, magnetic field lines are conventionally drawn from : A) north to south. B) south to north.
C) either way.
16. All other things being the same, strings that have more mass than other strings will produce:
A) higher frequency notes. B) lower frequency notes. C) the same frequency notes.
17. A wave travels an average distance of 1 meter in 1 second with a frequency of 1 hertz. Its amplitude is
A) less than 1 meter. B) 1 meter. C) more than 1 meter. D) not enough information to say.
18. Compared to the resistance of two resistors connected in series, the same two resistors connected in parallel have: A) more resistance. B) less resistance. C) the same resistance.
19. Two lamps, one with a thick filament and one with a thin filament, are connected in parallel to a battery. The voltage is greatest across the lamp with the: A) thick filament. B) thin filament. C) both voltages are the same.