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WorksheetsPower Electronics Activity
Total questions: 17
Worksheet time: 13mins
An SCR is considered to be a semi controlled device because_____________
it can be turned OFF but not ON with a gate pulse.
it conducts only during one half cycle of an alternating current wave.
it can be turned ON but not OFF with a gate pulse.
it can be turned ON only during one half cycle of an AC.
A single phase full bridge inverter can operated in load commutation mode in case load consist of_______
RL.
RLC underdamped.
RLC overdamped.
RLC critically damped RLC critically damped
A TRIAC is_______
3 terminal bidirectional switch
3 terminal bilateral switch
2 terminal switch
2 terminal bilateral switch
A silicon controlled rectifier (SCR) is a_______
Unijunction device
Device with three junction
Device with four junction
None of the above
A thyristor is basically_____
PNPN device
A set of SCRs
A combination of diac and triac
A set of SCR, diac and a triac
The triple frequency of a six-phase half wave rectifier for 220 V, 60 Hz input will be_____
2160 Hz
720 Hz
360 Hz
180 Hz
A step up chopper has input voltage 110 V and output voltage 150 V. The value of duty cycle is_______
0.32
0.67
0.45
0.27
If holding current of a thyristor is 2 mA then latching current should be____
0.02
0.001
0.004
0.002
The Inverter can be classified as________
Current Source Inverter
Voltage Source Inverter
Both Current Source & Voltage Source Inverter
None of above
In the ___________ type of chopper, two stage conversions takes place.
AC-DC
AC link
DC link
None of the mentioned
A chopper is______
Time ratio controller
AC to DC converter
DC transformer
High speed semiconductor switch
What is the duty cycle of a chopper?
Ton/Toff
Ton/T
T/Ton
Toff x Ton
If T is the time period for a chopper circuit and α is its duty cycle, then the chopping frequency is_____
Ton/α
Toff/α
α/Toff
α/Ton
SMPS is used for
obtaining controlled ac power supply
switch from one source to another
storage of dc power
obtaining controlled dc power supply
Static UPS requires __________
only rectifier
none of the mentioned
both inverter and rectifier
only inverter
Usually __________ batteries are used in the UPS systems.
NC
Li-On
Lead acid
All of the mentioned
This test activity is useful in order to recall the basic concepts.
Strongly Agree
Agree
Neither Agree nor Disagree
Disagree
