Lineman Electrical Theory and Principles 2

Question 1

A single-phase transformer has a primary voltage of 7,200V and a secondary voltage of 240V. What is the turns ratio?

Accepted Answer

30:1

Answer

10:1

Answer

20:1

Answer

40:1

Question 2

What formula is used to calculate electrical power in a DC circuit?

Accepted Answer

P = V × I

Answer

P = V / I

Answer

P = V × R

Answer

P = I / V

Question 3

Inductive reactance (XL) in an AC circuit increases as frequency:

Accepted Answer

Increases

Answer

Decreases

Answer

Remains constant

Answer

Reaches resonance

Question 4

What is the RMS (root mean square) voltage of a standard US 120V AC outlet in relation to its peak voltage?

Accepted Answer

Peak voltage is approximately 1.414 times the RMS voltage

Answer

Peak voltage equals RMS voltage

Answer

Peak voltage is exactly twice the RMS voltage

Answer

RMS voltage is 1.732 times the peak voltage

Question 5

Kirchhoff's Current Law (KCL) states that at any node in a circuit:

Accepted Answer

The sum of all currents entering equals the sum of all currents leaving

Answer

Voltage is equal at all branches

Answer

Total resistance equals total reactance

Answer

Power dissipated equals power supplied to each branch

Question 6

Which type of power is measured in volt-amperes reactive (VAR)?

Accepted Answer

Reactive power

Answer

True power

Answer

Apparent power

Answer

Real power

Question 7

A conductor carrying 200 amps over a resistance of 0.05 ohms will dissipate how much power as heat?

Accepted Answer

2,000 watts

Answer

500 watts

Answer

1,000 watts

Answer

4,000 watts