Electricity Oral 1

Question 1

Which law of electricity is the most important for an aircraft mechanic to know?

Answer 1

Ohm’s Law

Question 2

What are the elements of Ohm’s law?

Answer 2

E = IR
E = Voltage
I = Current flowing through the conductor
R = Resistance

Question 3

What is voltage?

Answer 3

The “pressure” pushing electricity through a circuit

Question 4

What is the basic unit of voltage?

Answer 4

Volt (V)

Question 5

What instrument is used to measure voltage?

Answer 5

A Voltmeter

Question 6

To measure voltage, is a voltmeter placed in series or in parallel with the source of voltage?

Answer 6

In parallel

Question 7

What is electrical current?

Answer 7

The flow of charged particles.

Question 8

What is the basic unit of current flow?

Answer 8

Ampere (A)

Question 9

What part of an amp is a milliamp?

Answer 9

1/1000 (One onethousandth)

Question 10

What instrument is used to measure current flow?

Answer 10

Ammeter

Question 11

What two things happen when current flows through a conductor?

Answer 11

Heat is generated and a magnetic field surrounds the conductor

Question 12

To measure current through a component, is an ammeter placed in parallel or in series with the component?

Answer 12

In series

Question 13

What is meant by resistance in an electrical circuit?

Answer 13

A force that counteracts the flow of current

Question 14

What is the basic unit of electrical resistance?

Answer 14

Ohm (Ω)

Question 15

What is a megaohm?

Answer 15

The equivalent of one million Ohms

Question 16

What four things affect the resistance of an electrical conductor?

Answer 16

Conductor material, Length of wire, Cross-sectional area, Temperature

Question 17

What instrument is used to measure electrical resistance?

Answer 17

Ohmmeter

Question 18

How can you tell the resistance of a composition resistor?

Answer 18

By reading the colored bands

Question 19

What is meant by continuity in an electrical circuit?

Answer 19

The presence of a complete path for current flow

Question 19

What instrument is used to measure continuity in an electrical circuit?

Answer 19

Ohmmeter

Question 20

When measuring resistance of a component with an ohmmeter, should the circuit be energized?

Answer 20

No, resistance is measured with the circuit’s power turned off

Question 21

What three things must an electric circuit contain?

Answer 21

A conductor, an electrical source, and a load

Question 22

What are three types of DC circuits with regard to the placement of the various circuit components?

Answer 22

Series DC circuit, series-parallel DC circuit, and parallel DC circuit

Question 23

What is the name of the law that describes the relationship in an electrical circuit of voltage, current and resistance?

Answer 23

Ohm’s law

Question 24

What is the basic equation of Ohm’s law?

Answer 24

E = IR

Question 25

What formula is used to find current when voltage and resistance are known?

Answer 25

I = E/R

Question 26

What formula is used to find resistance when voltage and current are known?

Answer 26

R = E/I

Question 27

What happens to the current in a DC circuit if the voltage is increased but the resistance remains the same?

Answer 27

The current will double

Question 28

What is the voltage across each resistor connected in parallel across a 12-volt battery?

Answer 28

12 Volts

Question 28

What happens to the current in a conductor if the length of the conductor is doubled with all other parameters unchanged?

Answer 28

The current would be halved

Question 29

How much current flows through each of the three resistors connected in series if the total current is 3 amps?

Answer 29

3 amps

Question 30

What is the total resistance of three 12-ohm resistors connected in series?

Answer 30

36Ω (Ohms)

Question 31

What is the total resistance of three 12-ohm resistors connected in parallel?

Answer 31

4 Ohms