Questions and answers for exam Preparation

MCQs

Total Questions : 327 | Page 31 of 33 pages

Question 301. The apparent power drawn by an A.C. circuit is 10 kVA and active power is 8 kW. The reactive power in the circuit is_________?

4 kVAR
6 kVAR
8 kVAR
16 kVAR

Discuss Question

Answer: Option B. -> 6 kVAR
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 302. In AC. circuits, laminated iron is invariably used in order to__________?

reduce eddy current loss
increase heat radiation
make assembly cheap and easier
reduce circuit permeability

Discuss Question

Answer: Option A. -> reduce eddy current loss
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 303. A parallel AC. circuit in resonance will__________?

have a high voltage developed across each inductive and capacitive section
have a high impedance
act like a resistor of low value
have current in each section equal to the line current

Discuss Question

Answer: Option B. -> have a high impedance
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 304. All definitions of power factor of a series R-L-C circuit are correct except__________?

ratio of net reactance and impedance
ratio of kW and kVA
ratio of J and Z
ratio of W and VA

Discuss Question

Answer: Option A. -> ratio of net reactance and impedance
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 305. The effective resistance of an iron-cored choke working on ordinary supply frequency is more than its true resistance because of____________?

iron loss in core
skin effect
increase in temperature
capacitive effect between adjacent coil turns

Discuss Question

Answer: Option A. -> iron loss in core
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 306. The ratio of active power to apparent power is known as factor__________?

demand
load
power
form

Discuss Question

Answer: Option C. -> power
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 307. A pure inductance connected across 250 V, 50 Hz supply consumes 100 W. This consumption can be attributed to_________?

the big size of the inductor
the reactance of the inductor
the current flowing in the inductor
the statement given is false

Discuss Question

Answer: Option D. -> the statement given is false
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 308. The input of an A.C. circuit having power factor of 0.8 lagging is 40 kVA The power drawn by the circuit is__________?

12 kW
22 kW
32 kW
64 kW

Discuss Question

Answer: Option C. -> 32 kW
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 309. In an AC. circuit, a low value of kVAR compared with kW indicates_________?

low efficiency
high power factor
unity power factor
maximum load current

Discuss Question

Answer: Option B. -> high power factor
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 310. If a sinusoidal wave has frequency of 50 Hz with 30 A r.m.s. current which of the following equation represents this wave_________ ?