Basic Electricity

Question 1

What is the most important law applicable to the study of electricity?

Answer 1

Ohm’s Law E= I x R

Question 2

What are the elements of ohms law?

Answer 2

Voltage, current, resistance

Question 3

what are four sources of electrical energy?

Answer 3

Thermal, light, pressure and chemical

Question 4

what does an electrical circuit consist of?

Answer 4

A source, resistance or load, and conductors

Question 5

what represents capacitance in an AC circuit?

Answer 5

Capacitor

Question 6

what is the function of a capacitor?

Answer 6

to store electricity

Question 7

what is the unit of measure for capacitance?

Answer 7

Farad

Question 8

what is the standard unit of measure for frequency?

Answer 8

Hertz

Question 9

what is the basic component that only allows current to flow in one direction?

Answer 9

Diode (acts like a check valve)

Question 10

What is inductance?

Answer 10

opposition to the flow of current in an AC circuit offered by a coil

Question 11

What is an example of an inductor in a magneto?

Answer 11

the Coil

Question 12

what is impedance?

Answer 12

The total resistance in a circuit

Question 13

what causes opposition to the flow of current in an AC circuit?

Answer 13

Inductive, and capacitive reactance

Question 14

What is the unit of measurement for impedance?

Answer 14

Ohms

Question 15

what is a general purpose of a resistor?

Answer 15

to limit current

Question 16

how may the value of a small, fixed resistor be determined?

Answer 16

By the color bands of the resistor

Question 17

what are the two things that happen when current flows through a conductor?

Answer 17

Magnetic field is generated and the conductor heats up

Question 18

what is the common name for the lines of force that make up a field surrounding a magnet?

Answer 18

Magnetic flux lines

Question 19

what is the concept that describes the relationship between electricity and magnetism?

Answer 19

Electromagnetism

Question 20

what are the four factors that affect the resistance of an electrical conductor?

Answer 20

Wire gauge, length, temperature, and material

Question 21

What is the unit of measurement of power in a DC circuit?

Answer 21

the Watt. P = I x E

Question 22

What is a kilowatt?

Answer 22

1,000 Watts Kilo means thousand

Question 23

In a DC circuit, what occurs when voltage is increased while resistance remains constant?

Answer 23

There will be an increase in current.

Question 24

What are the three types of DC electrical circuits?

Answer 24

Series, compound, parallel

Question 25

A 24-Volt lead acid battery has how many cells ?

Answer 25

12 cells each is approx. 2 volts

Question 26

what are the units that a battery capacity is measured in?

Answer 26

Ampere-hours

Question 27

what should be the specific gravity of the electrolyte in a fully charge lead acid battery?

Answer 27

Should be between 1.275 and 1.300

Question 28

what instrument is used to determine specific gravity of electrolyte in lead acid battery?

Answer 28

Hydrometer

Question 29

why can a hydrometer not be used to determine the charge of NiCad battery?

Answer 29

The specific gravity of the electrolyte and NiCad battery does not change appreciatively during charge or discharge.

Question 30

When using a hydrometer to check the charge of a lead acid battery, at what temperature must a correction factor be applied to the reading?

Answer 30

above 90°F and below 70°F adjustments must be made

Question 31

what is electromagnetic induction?

Answer 31

The transfer of electrical energy by means of magnetic field. Transferring voltage from one conductor to another without physical touching.

Question 32

How are battery compartments protected against corrosion?

Answer 32

They are coated with special corrosion resistant paint such as bituminous paint.

Question 33

What should be the correct electrolyte level in a properly serviced battery?

Answer 33

It should be approximately 3/8 of an inch above the plates. If battery has baffle plates above cell plates, the electrolyte levels should be up to the hole in the baffle plate in each cell.

Question 34

What are paralleling generators and how is the load distributed?

Answer 34

When two or more generators are operated at the same time to supply power for a load that must be shared equally.

Question 35

Describe a trip free circuit breaker?

Answer 35

Is impossible to manually hold circa close when excessive current is flowing

Question 36

can you store NiCad and lead acid batteries together?

Answer 36

no because cross contamination can occur

Question 37

what is the result of an imbalance cell in a NiCad battery?

Answer 37

Current will increase across the cell causing it to heat up

Question 38

what happens to the specific gravity of electrolyte and lead acid battery when the temperature changes?

Answer 38

it follows temperature high temp = higher specific gravity reading low temp = lower specific gravity reading

Question 39

What is an LED?

Answer 39

Light Emitting Diode

Question 40

What is an SLA battery?

Answer 40

Sealed Lead Acid Battery

Question 41

What is the basic unit of measure for inductance?

Answer 41

Henry

Question 42

What prevents reverse current flow in a DC alternator?

Answer 42

Reverse current cutout

Question 43

How many wires may be installed in a single terminal lug?

Answer 43

4

Question 44

how do you identify wire types?

Answer 44

Lettering on the insulation

Question 45

what is the max number of terminals I can be attached to a terminal strip stud?

Answer 45

More than four terminal lugs or three terminal lugs and a bus bar