AC circuits MCQ with Answers

16) What is the purpose of phase sequence meter?

Answer is:

To ensure the correct phase sequence of 3 phase system

17) Calculate the apparent power of a star connected 3 phase load, if it is connected across 3 phase 415volt/50Hz supply at 0.8 p.f and the phase current is 10 Amps

Answer is:

7.188 KVA

18) What is the P.F if one of the wattmeters reading is zero and the other reads total power in 2 wattmeter method of 3 phase power measurement?

Answer is:

0.5

19) Which electrical term is defined as the total opposition to current in AC parallel circuit?

Answer is:

Impedance

Explanation:

Impedance (symbol Z) is a measure of the overall opposition of a circuit to current, in other words: how much the circuit impedes the flow of charge. It is like resistance, but it also takes into account the effects of capacitance and inductance. Impedance is measured in ohms.

20) In a 3 phase system, if the active power is 4 kw and the apparent power is 5 KVA, calculate the reactive power?

Answer is:

16) What is the purpose of phase sequence meter?

To ensure the correct phase sequence of 3 phase system

17) Calculate the apparent power of a star connected 3 phase load, if it is connected across 3 phase 415volt/50Hz supply at 0.8 p.f and the phase current is 10 Amps

7.188 KVA

18) What is the P.F if one of the wattmeters reading is zero and the other reads total power in 2 wattmeter method of 3 phase power measurement?

0.5

19) Which electrical term is defined as the total opposition to current in AC parallel circuit?

Impedance

20) In a 3 phase system, if the active power is 4 kw and the apparent power is 5 KVA, calculate the reactive power?

3 KVAR