EC 311 Q1

Which terminal does not belong to the SCR?

• Anode

• Gate

• Base

• Cathode

Choose the false statement.

• SCR is a bidirectional device

• SCR is a controlled device

• In SCR the gate is the controlling terminal

• SCR are used for high-power applications

In the SCR structure the gate terminal is located

• near the anode terminal

• near the cathode terminal

• in between the anode & cathode terminal

• none of the mentioned

If the cathode of an SCR is made positive with respect to the anode & no gate current is applied then

• all the junctions are reversed biased

• all the junctions are forward biased

• only the middle junction is forward biased

• only the middle junction is reversed biased

For an SCR in the reverse blocking mode, (practically)

• leakage current does not flow

• leakage current flows from anode to cathode

• leakage current flows from cathode to anode

• leakage current flows from gate to anode

With the anode positive with respect to the cathode & the gate circuit open, the SCR is said to be in the

• reverse blocking mode

• reverse conduction mode

• forward blocking mode

• forward conduction mode

The forward break over voltage is the

• anode-cathode voltage at which conduction starts with gate signal applied

• anode-cathode voltage at which conduction starts with no gate signal applied

• gate voltage at which conduction starts with no anode-cathode voltage

• gate voltage at which conduction starts with anode-cathode voltage applied

Among the following, the most suitable method to turn on the SCR device is the

• gate triggering method

• dv/dt triggering method

• forward voltage triggering method

• temperature triggering method

The value of anode current required to maintain the conduction of an SCR even though the gate signal is removed is called as the

• holding current

• latching current

• switching current

• peak anode current

________ are semiconductor thyristor devices which can be turned-on by light of appropriate wavelengths.

• GTOs

• LASERs

• MASERs

• LASCRs