1. In thyristor, holding current is:
a) more than the latching current
b) less than the latching current
c) equal to latching current
d) none of the above
2. When a thyristor turn on, the gate drive:
a) can be turned down but thyristor remains in on position
b) cannot be turned down as thyristor will be turned off
c) gate drive has no impact on starting and turning off the thyristor
d) none of the above
3. A thyristor can be termed as:
a) DC switch
b) AC switch
c) both AC and DC switch
d) none of the above
4. During forward blocking state, a thyristor is associated with:
a) large current and low voltage
b) low current and large voltage
c) medium current and large voltage
d) None of the above
5. Turn-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
d) gate current becomes zero
6. A forward voltage can be applied to an SCR after its:
a) anode current reduces to zero
b) gate recovery time
c) reverse recovery time
d) anode voltage reduces to zero
7. In a thyristor, the magnitude of the anode current will:
a) increase if the gate current is increased
b) decrease if the gate current is decreased
c) increase if gate current is decreased
d) no change with the variation of the gate current
8. In a thyristor, ratio of latching current to holding current is:
a) 0.4
b) 1.0
c) 2.5
d) 4.0
9. Once SCR starts conducting a forward current, its gate losses control over:
a) anode circuit voltage only
b) anode circuit current only
c) anode circuit voltage and current
d) none of the above
10. On state voltage drop across thyristor used in a 230 V supply system is of the order:
a) 110-115V
b) 250 V
c) 1- 1.5 V
d) none of the above
a) more than the latching current
b) less than the latching current
c) equal to latching current
d) none of the above
2. When a thyristor turn on, the gate drive:
a) can be turned down but thyristor remains in on position
b) cannot be turned down as thyristor will be turned off
c) gate drive has no impact on starting and turning off the thyristor
d) none of the above
3. A thyristor can be termed as:
a) DC switch
b) AC switch
c) both AC and DC switch
d) none of the above
4. During forward blocking state, a thyristor is associated with:
a) large current and low voltage
b) low current and large voltage
c) medium current and large voltage
d) None of the above
5. Turn-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
d) gate current becomes zero
6. A forward voltage can be applied to an SCR after its:
a) anode current reduces to zero
b) gate recovery time
c) reverse recovery time
d) anode voltage reduces to zero
7. In a thyristor, the magnitude of the anode current will:
a) increase if the gate current is increased
b) decrease if the gate current is decreased
c) increase if gate current is decreased
d) no change with the variation of the gate current
8. In a thyristor, ratio of latching current to holding current is:
a) 0.4
b) 1.0
c) 2.5
d) 4.0
9. Once SCR starts conducting a forward current, its gate losses control over:
a) anode circuit voltage only
b) anode circuit current only
c) anode circuit voltage and current
d) none of the above
10. On state voltage drop across thyristor used in a 230 V supply system is of the order:
a) 110-115V
b) 250 V
c) 1- 1.5 V
d) none of the above
