1. An object 5 millimeters high is located 15 millimeters in front of
a plane mirror. How far from the mirror is the image located?
A. 5.0 millimeters C. 15 millimeters
B. 7.5 millimeters D. 30 millimeters
2. Which of the following values represents an index of refraction
of an actual material?
A. 0 C.
3. Which one of the following types of electromagnetic radiation causes certain substances
A. Ultraviolet rays C. X rays
B. Infrared waves D. Cosmic rays
4. If a 72-candela light source is located at a distance of 3 meters from a surface, the
illuminance on the surface is
A. 8 lux. C. 216 lux.
B. 24 lux. D. 648 lux.
5. If you’re driving towards the sun late in the afternoon, you can reduce the glare from the
road by wearing sunglasses that permit only the passage of light that’s
A. polarized in a vertical plane. C. dispersed in a vertical plane.
B. polarized in a horizontal plane. D. dispersed in a spherical plane.
6. The term angle of deviation is used in reference to
A. a polarizer. C. a lens.
B. a prism. D. an analyzer.
7. According to the information in your study unit, which of the following locations requires
the highest illuminance?
A. A residential stairway C. A bank lobby
B. A school locker room D. A study area
8. The unit for measuring the rate at which light energy is radiated from a source is the
A. Angstrom. C. lumen.
B. lux. D. candela.
9. Compared to yellow light, orange light has
A. the same frequency. C. a longer wavelength.
B. a faster wave velocity. D. a different polarization.
10. The image formed by a convex spherical mirror will always be
A. inverted and smaller than the object.
B. upright and smaller than the object.
C. inverted and larger than the object.
D. upright and larger than the object
11. When an object is placed 8 millimeters from a concave spherical mirror, a clear image
can be projected on a screen 16 millimeters in front of the mirror. If the object has a height
of 4 millimeters, the height of the image is
A. 2 millimeters. C. 8 millimeters.
B. 4 millimeters. D. 12 millimeters.
12. Which of the following lenses is a converging lens?
A. Double-convex lens C. Plano-concave lens
B. Spherical-convex lens D. Convexo-concave lens
13. A virtual image produced by a lens is always
A. larger than the object. C. located in front of the lens.
B. smaller than the object. D. located in the back of the lens.
14. In which of the following materials is the velocity of light greatest?
A. Air C. Crown glass
B. Water D. Fused quartz
15. If the distance from a converging lens to the object is less than the focal length of the lens,
the image will be
A. real, inverted, and larger than the object.
B. real, inverted, and smaller than the object.
C. virtual, upright, and larger than the object.
D. virtual, upright, and smaller than the object.
16. When a simple magnifying glass is used properly, the image will be formed
A. just inside the focal length of the lens.
B. about 250 millimeters in front of the lens.
C. at the focal point of the lens.
D. about 500 millimeters behind the lens.
17. When the image of a distant object is brought into focus in front of a person’s retina,
the defect is called
A. nearsightedness. C. chromatic aberration.
B. farsightedness. D. spherical aberration.
18. Reflecting telescopes are popular because they’re
A. more powerful than a refracting telescope.
B. smaller than a refracting telescope.
C. easier to build than a refracting telescope.
D. more durable than a refracting telescope
19. In any one material, all electromagnetic waves have the same
A. amplitude. C. wavelength.
B. frequency. D. velocity.
20. Which of the following occurs when light is reflected from a rough or unpolished surface?
A. The original pattern of the light is distorted.
B. The original pattern of the light is preserved.
C. The angle of reflection is less than the angle of incidence.
D. The angle of reflection is greater than the angle of incidence.
21. An object is located 51 millimeters from a diverging lens. The object has a height of
13 millimeters and the image height is 3.5 millimeters. How far in front of the lens is
the image located?
A. 1.12 millimeters C. 51 millimeters
B. 13.7 millimeters D. 189 millimeters
22. A failure of the red-sensitive nerves in the eye to respond to light properly causes
A. astigmatism. C. chromatic aberration.
B. farsightedness. D. color blindness.
23. When a beam of light passes at an oblique angle into a material of lower optical density,
the angle of incidence is
A. less than the angle of reflection.
B. less than the angle of refraction.
C. greater than the angle of reflection.
D. greater than the angle of refraction.
24. Rays of light incident on a lens and parallel to the principal axis of the lens converge
A. at the center of curvature of the lens. C. in front of the lens.
B. at the focal point of the lens. D. in back of the lens.
25. If an object 18 millimeters high is placed 12 millimeters from a diverging lens and the
image is formed 4 millimeters in front of the lens, what is the height of the image?
A. 6 millimeters C. 14 millimeters
B. 8 millimeters D. 22 millimeters
ELECTICITY AND ELECTRONICS
1. If one body is positively charged and another body is negatively
charged, free electrons tend to
A. move from the negatively charged body to the positively
B. move from the positively charged body to the negatively
C. remain in the negatively charged body.
D. remain in the positively charged body.
2. A battery consists of five dry cells connected in series. If the
voltage developed by each cell is 1.5 V, the total voltage
developed by the battery is
A. 0.3 V. C. 5.0 V.
B. 1.5 V. D. 7.5 V.
3. The grid in a high-vacuum triode is usually kept negatively charged with respect to the
cathode so that the electrons may be
A. accelerated toward the anode.
B. accelerated toward the cathode.
C. attracted to the anode instead of the grid.
D. attracted to the cathode instead of the grid.
4. An example of an atom that has no charge is one that has
A. 2 protons, 2 electrons, and 1 neutron.
B. 1 proton, 2 electrons, and 3 neutrons.
C. 3 protons, 1 electron, and 3 neutrons.
D. 3 protons, 2 electrons, and 1 neutron.
5. If an electrically uncharged body is contacted by an electrically charged body, the
uncharged body will
A. develop the opposite charge as the charged body.
B. remain a neutrally charged body.
C. develop the same charge as the charged body.
D. neutralize the charged body.
6. What bias conditions must be present for the normal operation of a transistor amplifier?
A. The emitter-base junction must be reverse biased, and the collector-base junction must
be forward biased.
B. The emitter-base junction must be forward biased, and the collector-base junction must
be reverse biased.
C. Both junctions must be reverse biased.
D. Both junctions must be forward biased.
7. When an electric current flows through a long conductor, each free electron moves
A. from one end of the conductor to the other end.
B. with a speed of 300,000,000 m/s.
C. back and forth between the ends of the conductor.
D. through a relatively short distance.
8. If the resistance of an electric circuit is 12 ohms and the voltage in the circuit is 60 V, the
current flowing through the circuit is
A. 0.2 A. C. 60 A.
B. 5 A. D. 720 A.
9. Electrons are emitted from a conductor when the conductor is
A. exposed to weak light.
B. cooled rapidly.
C. bombarded by high-speed electrons.
D. subjected to a small voltage
10. A circuit contains two devices that are connected in parallel. If the resistance of one
of these devices is 12 ohms and the resistance of the other device is 4 ohms, the total
resistance of the two devices is
A. 0.0625 ohms. C. 3 ohms.
B. 0.333 ohms. D. 16 ohms.
11. When a PNP transistor is connected in a circuit in the manner shown in Figure 52 of this
study unit, it can be used as a power amplifier because
A. the output current will be much smaller than the input current.
B. the output current will be much larger than the input current.
C. the output voltage will be much smaller than the input voltage.
D. the output voltage will be much larger than the input voltage.
12. The function of a capacitor in an electric circuit is to
A. allow current flow between its plates. C. increase circuit power.
B. measure the amount of current in the circuit. D. store electric charges.
13. In a cathode ray tube, the number of electrons that reach the fluorescent screen is
controlled by the
A. anode. C. deflecting plate.
B. cathode. D. grid.
14. Which of the following frequencies falls in the range of RF waves used by commercial
radio broadcasting stations?
A. 60 Hz C. 600,000 Hz
B. 6,000 Hz D. 6,000,000 Hz
15. To use your left hand to determine the direction of the voltage developed in a moving
conductor in a stationary magnetic field, you must point your
A. thumb in the direction of the magnetic flux.
B. thumb in the direction of the electromagnetic force.
C. forefinger in the direction of the lines of force.
D. forefinger in the direction of the motion.
16. A complete circuit contains two parallel-connected devices and a generator for providing
the electromotive force. The resistance of the first device is 12 ohms, the resistance of the
second device is 4 ohms, and the voltage developed by the generator is 40 V. What is the
magnitude of the current flowing through the first device?
A. 3.33 A C. 10 A
B. 8 A D. 13.32 A
17. A transformer has a primary voltage of 115 V and a secondary voltage of 24 V. If the
number of turns in the primary is 345, how many turns are in the secondary?
A. 8 C. 690
B. 72 D. 1,653
18. Look at the circuit shown in Figure A-1. If you want to stop the current flow through Device
3 in the circuit, which one of the following single switches should you open?
A. Switch S2 C. Switch S4
B. Switch S3 D. Switch S5
19. An electric heating element is connected to a 110 V circuit and a current of 3.2 A is
flowing through the element. How much energy is used up during a period of 5 hours by
A. 352 Wh C. 1,760 Wh
B. 550 Wh D. 2,580 Wh
20. The magnitude of the voltage induced in a conductor moving through a stationary
magnetic field depends on the _______ and the _______ of the conductor.
A. length, speed C. resistance, current
B. distance, circumference D. color, capacitan
21. If a bar of copper is brought near a magnet, the copper bar will be
A. attracted by the magnet. C. repelled by the magnet.
B. unaffected by the magnet. D. made into an induced magnet.
22. When all parts of a circuit are composed of conducting materials, the circuit is said to be
A. parallel. C. open.
B. shorted. D. closed.
23. When an electron is displaced in a semiconductor, the hole that’s left behind is
A. attracted to the negative terminal of the voltage source.
B. incapable of carrying a charge.
C. attracted to the anode of the voltage source.
D. considered an impurity in the crystal.
24. Including a full-wave rectifier in an AC circuit will yield a(n) _______ current.
A. intermittent direct C. continuous direct
B. intermittent alternating D. continuous alternating
25. Suppose that you’re facing a straight current-carrying conductor, and the current is flowing
toward you. The lines of magnetic force at any point in the magnetic field will act in
A. the same direction as the current.
B. a clockwise direction.
C. the direction opposite to the current.
D. a counterclockwise direction.