PC General Theory and Calculations 2

Question 1

A 240V single-phase circuit draws 15A. What is the apparent power in VA?

Accepted Answer

3,600 VA

Answer

1,800 VA

Answer

240 VA

Answer

960 VA

Question 2

Which formula correctly expresses Ohm's Law for current?

Accepted Answer

I = V / R

Answer

I = R / V

Answer

I = V × R

Answer

I = P / R

Question 3

Three resistors of 6Ω, 12Ω, and 4Ω are connected in parallel. What is the total equivalent resistance?

Accepted Answer

2 Ω

Answer

22 Ω

Answer

7.33 Ω

Answer

1.5 Ω

Question 4

What is the power factor of a purely resistive AC circuit?

Accepted Answer

1.0

Answer

0

Answer

0.5

Answer

0.707

Question 5

A conductor has a resistance of 0.5Ω and carries 20A. What is the power dissipated as heat?

Accepted Answer

200 W

Answer

10 W

Answer

0.025 W

Answer

40 W

Question 6

In a series RLC circuit at resonance, which statement is true?

Accepted Answer

Inductive and capacitive reactances are equal and cancel

Answer

Inductive reactance exceeds capacitive reactance

Answer

Capacitive reactance exceeds inductive reactance

Answer

Total impedance equals the sum of XL and XC

Question 7

What does a lagging power factor indicate about a load?

Accepted Answer

The load is predominantly inductive

Answer

The load is purely resistive

Answer

The current leads the voltage

Answer

The load is predominantly capacitive