1. In normal operation of an SCR, gate is _____________w.r.t. cathode?
A. Positive
B. Negative
C. At zero potential
D. None of the above
✅ The correct answer is option A.
SCR (Silicon Controlled Rectifiers) MCQs
2. An SCR has __________ pn junctions?
A. Two
B. Three
C. Four
D. None of the above
✅ The correct answer is option B.
3. When SCR is OFF, the current in the circuit is ________________?
A. Exactly zero
B. Small leakage current
C. Large leakage current
D. None of the above
✅ The correct answer is option B.
4. If gate current is increased, then anode-cathode voltage at which SCR closes_________________?
A. Is decreased
B. Is increased
C. Remains the same
D. None of the above
✅ The correct answer is option A.
5. If firing angle in an SCR circuit is increased, the output _____________?
A. Remains the same
B. Is increased
C. Is decreased
D. None of the above
✅ The correct answer is option C.
6. We can control a.c. power in a load by connecting ______________?
A. Two SCRs in series
B. Two SCRs in parallel
C. Two SCRs in parallel opposition
D. None of the above
✅ The correct answer is option C.
7. An SCR is turned off when ________________?
A. Anode current is reduced to zero
B. Gate voltage is reduced to zero
C. Gate is reverse biased
D. None of the above
✅ The correct answer is option A.
8. An SCR has ___________semiconductor layers?
A. Two
B. Three
C. Four
D. None of the above
✅ The correct answer is option C.
9. An SCR has three terminals viz ________________?
A. Cathode, anode, gate
B. Anode, cathode, grid
C. Anode, cathode, drain
D. None of the above
✅ The correct answer is option A.
10. An SCR is sometimes called ____________?
A. Triac
B. Diac
C. Unijunction transistor
D. Thyristor
✅ The correct answer is option D.