SCR - Electrical Engineering (MCQ) questions and answers

1.A thyristor is reserve biased .A positive gate pulse is applied. The Thyristor

A. will turn ON
B. may or may not turn ON
C. will turn on after sometime
D. will not turn ON

2. Mobility of charge carrier in a semiconductor depend on

A. Recombination Rate
B.Resistivity of Semiconductor
C. Temperature of semiconductor
D. Charge per carrier

3.The Anode current through a conducting SCR is 10 A. If its Gate Current is made One-fourth,then what will be the anode current?

A. 0A
B. 20A
C. 10A
D. 5A

4.consider the followinf devices: 1.SCR 2. GTO 3. BJT 4. MOSFET 5. IGBT Which of these devices do not belong to the family of transistor

A. 1,2and 3 only
B. 1 and 2 only
C. 2,3and 5 only
D.1,2,3,4and 5 only

5.In thyristor, the ratio of holding current to latching current is:

A.2.5
B. 1
C. 3
D. 0.4

6. In thyristor, the ratio of latching current to holding current is:

A.4
B.0.4
C. 1
D.2.5

7. Tuen -Off time of an SCR is measured from the instant

A. ANODE CURRENT BECOMES ZERO
B. ANODE VOLTAGE BECOMES ZERO
C. ANODE VOLTAGE AND ANODE CURRENT BECOMES ZERO AT THE SAME TIME
D. GATE CURRENT BECOME ZERO

8. Which of the following does not cause permanent damage of an SCR?

A.High current
B. high rate of rise of current
C. High temperature Rise
D. High rate of Rise of voltage