Silicon Controlled Rectifier - SCR MCQ Questions and Answers for Practice

1. An SCR combines the features of …………..

1. A rectifier and resistance
2. A rectifier and transistor
3. A rectifier and capacitor
4. None of the above

2. If the gate voltage of an SCR is removed, then the

1. anode current decreases
2. anode current does not decrease at all
3. anode current increases
4. cathode current increases

3. An SCR is turned off when …………..

1. Anode current is reduced to zero
2. Gate voltage is reduced to zero
3. Gate is reverse biased
4. None of the above

4. An SCR is turned off when

1. Anode current is reduced to zero
2. Gate voltage is reduced to zero
3. Gate is reverse biased
4. None of the above

5. An SCR can be used

1. as static conductor
2. for power control
3. for speed control of dc shunt motor
4. all of these

6. In the normal operation of an SCR, anode is …………… w.r.t. cathode

1. At zero potential
2. Negative
3. Positive
4. None of the above

7. With gate open, the maximum anode current at which SCR is turned off from ON condition is called

1. breakdown voltage
2. peak reverse voltage
3. holding current
4. latching current

8. The normal way to turn on a SCR is by ……………..

1. Breakover voltage
2. Appropriate anode current
3. Appropriate gate current
4. None of the above

9. The control element of an SCR is ………….

1. Cathode
2. Anode
3. Anode supply
4. Gate

10. When SCR starts conducting, which loses all control?

1. Cathode
2. Gate
3. Anode
4. None of the above

11. An SCR has three terminals viz ……………

1. Cathode, anode, gate
2. Anode, cathode, grid
3. Anode, cathode, drain
4. None of the above

12. In an SCR circuit, the angle of conduction can be changed by ……….

1. Changing anode voltage
2. Changing gate voltage
3. Reverse biasing the gate
4. None of the above

13. In an SCR circuit, the angle of conduction can be changed by

1. Changing anode voltage
2. Changing gate voltage
3. Reverse biasing the gate
4. None of the above

14. In an SCR circuit the supply voltage is generally ……….. that of breakover voltage

1. Equal to
2. Less than
3. Greater than
4. None of the above

15. In an SCR circuit, the supply voltage is generally ......... that of breakover voltage

1. Equal to
2. Less than
3. Greater than
4. None of the above