Q.196 Inductance L opposes changing in current during _____
A. stating interval
B. transient interval
C. normal
D. any of the above
Ans.: B
Q.197 apparent power is defined as the
A. the product of the rms values of voltage and current
B. the product of the average values of voltage and current
C. the product of the maximum values of voltage and current
D. the product of the instantaneous values of voltage and current
Ans.: A
Q.198 The true power is defined as the power equal to the ___.
A. power dissipated in ac circuit
B. power consumed by ac circuit
C. average power in L circuit
D. Average power in C circuit
Ans.: A
Q.199 The power taken by pure reactance in a circuit is called___
A. real power
B. reactive power
C. apparent power
D. reserve power
Ans.: B
Q.200 The apparent power is measured in
A. Wh
B. VA
C. VAR
D. I2R
Ans.: B
Q.201 which of the following is/are correct for real power?
A. real power = EI cos ф
B. it is expressed in watt
C. EI sin ф
D. Both A and B
Ans.: D
Q.202 The unit of reactive power is__
A. VAR
B. WAR
C. VA
D. Watt hour
Ans.: A
Q.203 Reactive power is given by__
A. Apparent power x sin ф
B. Apparent power = EI sin ф
C. Both A and B
D. apparent power = EI cos ф
Ans.: C
Q.204 Power factor is defined as
A. the ratio of resistance to impedance
B. cosine of angle between voltage and current
C. The ratio of real power to apparent power
D. all of the above
Ans.: D
Q.205 The value of power factor
A. always more than unity
B. can never more than unity
C. always less than unity
D. always unity
Ans.: B
Q.206 what are the effect of low power factor?
A. low power factors cause greater fall in the terminal voltage
B. due to low power factor, total current must be increased resulting in increase in resistive losses
C. low power factor limits the output of the generator and transformer
D. all of the above
Ans.: D
Q.207 Due to low power factor
A. the voltage regulation is greater than unity
B. the voltage regulation is less than unity
C. the voltage regulation is unity
D. the voltage regulation is infinite
Ans.: A
Q.208 what is the effect of lower power factor on efficiency?
A. increase
B. decrease
C. remains same
D. efficiency does not depend on power factor
Ans.: B
Q.209 due low power factor, high current drawn out by transformer and generator resulting in___
A. high out put
B. temperature rise
C. efficiency is increase
D. voltage regulation is decrease
Ans.: B
Q.210 The power factor is
A. leading
B. lagging
C. unity
D. all of the above and depend on type of load
Ans.: D