Worksheets1. Power Electronic Devices
Total questions: 20
Worksheet time: 20mins
The terminals of an SCR are:
Anode, Gate, Emitter
Anode, Cathode, Gate
Source, Drain, Gate
Collector, Base, Emitter
How many terminals does an SCR have?
2
3
4
1
An SCR is a
2-layer device
3-layer device
4-layer device
5-layer device
The SCR conducts when:
Anode is negative w.r.t cathode
Gate is made positive w.r.t cathode
Gate is made negative w.r.t cathode
No triggering is required
The process of turning OFF an SCR is called
Firing
Commutation
Clamping
Amplification
A DIAC has how many terminals?
2
3
4
1
DIAC conducts when
Forward voltage is applied
Reverse voltage is applied
Breakover voltage in either direction is reached
Gate pulse is applied
DIAC is mainly used for
Power amplification
Motor control
Triggering TRIACs
Rectification
TRIAC is a:
Unidirectional device
Bidirectional device
Photo device
Thyristor with only 2 terminals
TRIAC has how many terminals?
2
3
4
5
TRIAC is triggered by:
Gate pulse only during positive half cycle
Gate pulse only during negative half cycle
Gate pulse during both half cycles
Cannot be triggered by gate
The terminals of a TRIAC are:
A, K, G
M1, M2, G
C, E, B
S, D, G
The minimum current required to keep SCR in the ON state is called:
Latching current
Holding current
Leakage current
Trigger current
The gate of an SCR is always connected with respect to the:
Anode
Cathode
Collector
Source
SCR belongs to which family?
FET
BJT
Thyristor
MOSFET
Turn-off time of an SCR is the time required for:
Increasing gate current
Reaching conduction
Regaining forward blocking ability
Increasing anode current
DIAC conducts at:
Zero voltage
Only positive voltage
Breakover voltage
Gate pulse
DIAC symbol looks like:
Two diodes in series
Two diodes in parallel
Two diodes in anti-parallel
Two SCRs in anti-parallel
TRIAC can be triggered by gate pulse applied between:
M1–M2
Gate–M1
Gate–M2
Both b and c
TRIAC is used in:
DC motor control
AC lamp dimmers
Rectifiers
Amplifiers
