Theory Quiz

The potential difference between two conductors which are insulated from each other is measured in

Volts

(8023) (Refer to Figure 4.) How much power is being furnished to the circuit?

2,645 watts

Which term means .001 ampere?

Milliampere

.002KV equals

2\.0 volts.

What is the operating resistance of a 30-watt light bulb designed for a 28-volt system?

26 ohms.

Through which material will magnetic lines of force pass the most readily?

Iron

The voltage drop in a circuit of known resistance is dependent on

the amperage of the circuit.

Which symbol represents a variable resistor?

2

The unit of electrical pressure is the

volt

Which wire has the larger area, a 20-gage wire or a 10-gage wire?

A  10 gage wire.

A switch that can select either of two conditions for two circuits is called a ____ pole, ___ throw switch.

Double, double

The unit of electrical current is the

amp

The difference between a relay and a solenoid is in the core. A solenoid has _____ core.

movable

Fuses and circuit breakers are rated in the ____ they can take.

amps

The unit of electrical resistance is the

ohm

One ____ of electrical pressure will force one *__* of current flow through a resistance of one ____

volt, amp, ohm

Five forms of energy that can be converted into electricity are: \n A. coal \n B. light \n C. magnetism \n D. nuclear \n E. pressure \n F. heat \n G. chemical action

B, C, E, F, G

The resistance of a light bulb may be found by _____ the voltage across the bulb by the current through it.

dividing

Electrical movement in a conductor is considered to be at the speed of 

light

Electrons leave a source of electrical pressure at its ___ terminal and return at the ____ terminal.

negative, positive

The two metals which are the best conductors of electricity are; a. _____ b. _____

copper, silver

Four things that affect the resistance of a conductor are; \n A. length \n B. height \n C. density \n D. temperature \n E. ground \n F. cross-sectional area \n G. material \n H. weight \n I. color

A, D, F, G

Name the three components necessary in all electrical circuits.

Power, source, conductor.

Concerning Ohm’s law identify which statements are incorrect


1. Current is directly proportional to resistance
2. Resistance is directly proportional to voltage
3. Current is directly proportional to voltage
4. Resistance is inversely proportional to current

1, 2

100,000 ohms = ______ megohms.

0\.1

0\.005 A = ______ microamps

5000

The outer shell of an atom is called the _________ shell.

valance

What is the resistance of this resistor

630000

Which requires the most electrical power during operation?

Two lights requiring 3 amperes each in a 24 volt parallel systems.

How much power must a 24-volt generator furnish to a system which contains the following loads?|

UNIT                                                                 RATING

One motor (75 percent efficient)                   1/5 hp \n Three position lights                                       20 watts each \n One heating element                                         5 amp \n One anticollision light                                        3 amp

450 watts.

A 12-volt electric motor has 1,000 watts input and 1 horsepower output. Maintaining the same efficiency, how much input power will a 24-volt, 1-horsepower electric motor require? 

1,000 watts.

A 1-horsepower, 24-volt dc electric motor that is 80 percent efficient requires 932.5 watts. How much power will a 1-horsepower, 12-volt dc electric motor that is 75 percent efficient require?

**994.6 watts.**

Find the amount of power used by each of these components:

a. A 12 volt motor requiring 8 amperes = ___ watts.

b. Four 30 watt lamps in a 12 volt circuit = ___ watts.

c. Two light requiring 3 amperes each in a 24 volt parallel system = ____ watts.

d. A 1/10 horsepower, 24 volt motor which is 75% efficient = ___ watts.

96, 120, 144, 99.5

The power used by a bulb may be found by ______ the voltage across the bulb by the current through it.

multiplying

1 Horsepower = _____ watts

746