Complex AC MCQs

Question 1

In the R-L-C containing R = 4.5 SI, L = 0.06 H, C = 0.6 tff the power factor will be

Accepted Answer

leading

Answer

zero

Answer

lagging

Answer

unity

Question 2

The r.m.s. value of alternating current is given by steady (D.C.) current which when flowing through a given circuit for a given time produces

Accepted Answer

the same heat as produced by A.C. when flowwing through thesame circuit

Answer

the more heat than produced by A.C. when flowing through the same circuit

Answer

the less heat than produced by A.C. flowing through the same circuit

Answer

none of the above

Question 3

The double energy treansient occur in the

Accepted Answer

R-L-C circuit

Answer

purely inductive circuit

Answer

R-L circuit

Answer

R-C circuit

Question 4

The transient currents are associated with the

Accepted Answer

changes in the stored energy in the inductors and capacitors

Answer

impedance of teh circuit

Answer

applied voltage to the circuit

Answer

resistance of th circuit

Question 5

In the case of an unsymmetrical alternating current the average value must always be taken over

Accepted Answer

the whole cycle

Answer

unsymmetrical part of the wave from

Answer

the quarter cycle

Answer

the half cycle

Question 6

In a pure resistive circuit

Accepted Answer

current is in phase with the voltage

Answer

current lags behind the voltage by 900

Answer

current leads the voltage by 90?

Answer

current can lead or lag the voltage by 90?

Question 7

In a pure inductive circuit

Accepted Answer

the current lags behind the voltage by 90?

Answer

the current is in phase which the voltage

Answer

the current leads the voltage by 90?

Answer

the current canlead or lag by 90?

Question 8

Inductance of coil

Accepted Answer

increase with the increase in supply frequency

Answer

is unaffected by the supply frequency

Answer

decreases with the increase in supply frequency

Answer

becomes zero with the increase in supply frequency

Question 9

In an A.C. circuit always

Accepted Answer

apparent power is more than actual power

Answer

reactive power is more than apparent power

Answer

actual power is more than reactive power

Answer

reactive power is more than actual power