WorksheetsSCR and TRIAC Quiz
Total questions: 15
Worksheet time: 8mins
SCR is a:
Two-terminal device
Three-terminal device
Four-terminal device
Five-terminal device
The three terminals of an SCR are:
Anode, Cathode, Base
Anode, Cathode, Gate
Source, Drain, Gate
Emitter, Base, Collector
A TRIAC can conduct current in:
One direction only
Two directions
Three directions
Four directions
The device equivalent to two SCRs connected in anti-parallel is:
UJT
TRIAC
Diode bridge
MOSFET
In a UJT relaxation oscillator, triggering pulses for SCR are obtained from:
Inductor
Capacitor charging and discharging
Resistor
Transformer
The firing angle (α) of a phase-controlled rectifier controls:
Current gain
Output DC voltage
Frequency
Holding current
A half-wave controlled rectifier uses:
One SCR
Two SCRs
Four SCRs
Six SCRs
A DC chopper converts:
DC to AC
AC to DC
Fixed DC to variable DC
AC to variable frequency AC
In a step-up chopper, the output voltage is:
Less than input voltage
Equal to input voltage
Greater than input voltage
Zero
A single-phase bridge inverter consists of:
Two switching devices
Four switching devices
Six switching devices
Eight switching devices
The output of a single-phase bridge inverter is:
Pure DC
Pure AC sine wave
Square wave or PWM AC
Constant voltage
A cycloconverter converts:
AC to DC
DC to AC
AC to variable frequency AC
DC to DC
Cycloconverters are widely used in:
Lighting circuits
Motor speed control
Voltage regulation of batteries
Amplifiers
The minimum current required to keep SCR in the ON state is called:
Gate current
Holding current
Latching current
Peak current
The gate of a TRIAC can be triggered by:
Only positive voltage
Only negative voltage
Both positive and negative voltage
Zero voltage only
