Question 31 : A 1-phase half wave diode rectifier with R load, has input voltage of 240 V. The input power factor is
1. Unity
2. 0.707 lag
3. 0.56 lag
4. 0.865 lag
View Answer   Discuss with Members

Question 32 : The average value of the output voltage, in a 3-phase half wave diode rectifier with Vml as the maximum line voltage value, is given by the expression
1. Vml/3π
2. 2Vml/3π
3. 3Vml/2π
4. 3Vml
View Answer   Discuss with Members

Question 33 : In a three-phase half wave diode rectifier using 3 diodes,
1. All diodes conduct together
2. Only two diodes conduct at a time
3. Only one diode conducts at a time
4. None of the above mentioned
View Answer   Discuss with Members

Question 34 : A single-phase full wave rectifier is a
1. single pulse rectifier
2. multiple pulse rectifier
3. two pulse rectifier
4. three pulse rectifier
View Answer   Discuss with Members

Question 35 : In a 1-Phase HW diode rectifier with R load, the average value of load current is given by
Take Input (Vs) = Vm sinωt
1. Vm/R
2. Vm/2R
3. Vm/πR
4. Zero
View Answer   Discuss with Members

Question 36 : For a single phase, full bridge, diode rectifier excited from a 230 V, 50 Hz source. With R = 10 Ω & the inductance(L) large enough to maintain continues conduction, the average and rms values of diode currents will be
1. 7.85 A, 8 A
2. 10.35 A, 7.85 A
3. 10.35 A, 14.6 A
4. 8 A, 8 A
View Answer   Discuss with Members

Question 37 : Choose the correct statement
1. The AC component in the output of rectifier does the useful work
2. The AC component in the output of rectifier increases the efficiency of the system
3. The AC component in the output of rectifier causes ohmic losses
4. The AC component in the output of rectifier does not affect the operation
View Answer   Discuss with Members

Question 38 : In a half-wave rectifier, the
1. current & voltage both are bi-directional
2. current & voltage both are uni-directional
3. current is always uni-directional but the voltage can be bi-directional or uni-directional
4. current can be bi-directional or uni-directional but the voltage is always uni-directional
View Answer   Discuss with Members

Question 39 : A step-down delta-star transformer, with per-phase turns ratio of 5 is fed from a 3-phase 1100 V, 50 Hz source. The secondary of this transformer is connected through a 3-pulse type rectifier, which is feeding feeding an R load. Find the average value of output voltage.
1. 220 V
2. 257 V
3. 1100/√3 V
4. 206 V
View Answer   Discuss with Members

Question 40 : A 3-phase bridge rectifier charges a 240 V battery. The rectifier is given a 3-phase, 230 V supply. The current limiting resistance in series with the battery is of 8 Ω.
Find the average value of battery charging current.
1. 12.56 A
2. 8.82 A
3. 9.69 A
4. 6.54 A
View Answer   Discuss with Members