Expert: Spaceman - 3/2/2004

Question
my age is 25
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 charged body.
B) move from the positively charged body to the negatively charged body.
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 volts, 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-vaccum triode is usuall 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, & 1 neutron.
B)1 proton, 2 electrons, & 3 neutrons.
C) 3 protons, 1 electrons, & 3 neutrons.
D) 3 protons, 2 electrons, & 1 neutron.
5) If an electrically uncharged body is contacted by an electricaaly 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 transitor amplifier?
A) the emmitter-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 circut is 12 ohms and the voltage in the circut is 60 volts, the current flowing through the circut 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 circut 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 transitor is connected in a circut in the manner shown in figure 52 of this study unit, it can be used as as 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 that 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
B)measure the amount of current in the circuit.
C)increase circuit power.
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 one 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 Volts and a secondary voltage of 24 Volts. 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) An elecctric 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 the element?
A) 352 Wh        C) 1,760 Wh
B) 550 Wh        D) 2,580 Wh
19) 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,capacitance
20) If a bar of copper is brought near a magnet, the copper bar will be
A)attracted by the magnet
B)unaffected by the magnet.
C) repelled by the magnet.
D) made into an induced magnet.
21)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
22)When an electron is displaced in a semiconductor, the hole that is left behind is
A) attracted to the negative terminl of the voltage source.
B) incapable of carring a charge
C)atracted to the anode of the voltage source.
D) considered an impurity in the crystal.
23) 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
24)Suppose you're facing a straight current-carring 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.  

Answer
Hello Chrisitna :

Thanks for your questions!

I normally never answer homework questions, but here are a few of MY answers...

1. A
2. D
3. B
4. A
5. D
6. D
7. B
8. B
9. B
10. C

For more on basic electronic theory and to check my answers, visit:
1. www.play-hookey.com/dc_theory/
2. www.electronics-tutorials.com/ basics/basic-electronics.htm


Note: Please no more long questions like this! One question at a time.

My Best Wishes,
Spaceman