Basic Power Electronics (22427) Quiz

25 Questions | By Prafulgavde | Last updated: Mar 21, 2022 | Total Attempts: 68

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Basic Power Electronics (22427) Quiz - Quiz

Mr. Gavde P. B. M. E. (Electronics) (Lecturer in Electronics) Electronics & communication Department Government Polytechnic,Beed

Questions and Answers

1.

Latching current define as ........
- A.
  
  Minimum on state current required to keep the device in the on state after the triggering pulse has been removed SCR will not Turn off
- B.
  
  Minimum on state current required to keep the device in the on state after the triggering pulse has been removed SCR will remain Turn ON
- C.
  
  Minimum on state current required to keep the device in the on state after the triggering pulse has been removed SCR will Turn off
- D.
  
  Both 1 & 2
2.

Holding current define as .......
- A.
  
  It is mimimum forward anode current required to keep SCR on if the current fall below the holding level,then SCR remain in turn on
- B.
  
  It is mimimum forward anode current required to keep SCR on if the current fall below the holding level,then SCR turn off
- C.
  
  Both 1 & 2
- D.
  
  None of above
3.

I_a= α₂I_g+I_{cEo ^{/ (1-}}α) in this equation if α approaches to unity then anode current will be
- A.
  
  Zero
- B.
  
  Minimum
- C.
  
  Increases
- D.
  
  None of above
4.

If value of latching current is 12mA what is the value of holding current.....
- A.
  
  10mA
- B.
  
  13mA
- C.
  
  14mA
- D.
  
  15mA
5.

For 4000V,3000A GTO need .........gate current to Turn Off
- A.
  
  750A
- B.
  
  -750A
- C.
  
  780A
- D.
  
  -780A
6.

In TRIAC which mode is less sensitive
- A.
  
  Mode I & II
- B.
  
  Mode II & III
- C.
  
  Mode I & IV
- D.
  
  Mode III & IV
7.

Arrow in the MOSFET symbol indicates..........
- A.
  
  Direction of Hole flow
- B.
  
  Dirction of Current flow
- C.
  
  Direction of electron flow
- D.
  
  All of the above
8.

Power MOSFET is .....
- A.
  
  Voltage control Device
- B.
  
  Current control Device
- C.
  
  Both 1 & 2
- D.
  
  None of above
9.

In IGBT three terminals are .....
- A.
  
  Drain ,source & Gate
- B.
  
  Collector,Emitter & Gate
- C.
  
  Drain,Source& Emitter
- D.
  
  Both 1 & 2
10.

In which condition IGBT Turn on
- A.
  
  VGS>VGS(TH)
- B.
  
  VGS
- C.
  
  VGS=VGS(TH)
- D.
  
  VGS=0
11.

Interbase resistance (R_BB) in UJT exist between.....
- A.
  
  3K Ohm to 4K Ohm
- B.
  
  1K Ohm to 3k Ohm
- C.
  
  4K Ohm to 10k Ohm
- D.
  
  10K Ohm to 14k Ohm
12.

Intrinsic stand off ratio range in between .....
- A.
  
  0.2 to 0.4
- B.
  
  0.3 to 0.5
- C.
  
  0.9 to 1.3
- D.
  
  0.5 to 0.8
13.

Which device is called as uncontrolled rectifier
- A.
  
  SCR
- B.
  
  Diode
- C.
  
  BJT
- D.
  
  PUT
14.

In 2 quadrant converter polarity of output voltage can be either positive of negative however output current has one polarity only called as.......
- A.
  
  Full converter
- B.
  
  Semiconverter
- C.
  
  Dual Converter
- D.
  
  Both 1& 2
15.

Which one is not function of freewheeling diode......
- A.
  
  It prevent reversal of load voltage except for small voltage drop
- B.
  
  It convert AC to pulsating DC
- C.
  
  It transfer the load current away from the main rectifier,thereby allowing all of its thyristor to regain their blocking state
- D.
  
  None of above
16.

In three phase half wave controlled rectifier with resistive load primary is.....
- A.
  
  Star connection
- B.
  
  Transformer connection
- C.
  
  Delta connection
- D.
  
  Both 1 & 3
17.

In 3 phase half wave controlled rectifier conduction period for each thyristor is equal to ....
- A.
  
  60 degree
- B.
  
  80 degree
- C.
  
  100 degree
- D.
  
  120 degree
18.

If dc circuit of 240V is to be protected with 25V selenium cell then how many cells required
- A.
  
  10
- B.
  
  12
- C.
  
  14
- D.
  
  16
19.

For Thyristor overcurrent protection which is better option
- A.
  
  Selenium diode protection
- B.
  
  Snubber circuit protection
- C.
  
  Crowbar protection
- D.
  
  Metal oxide varistor
20.

How to turn off SCS
- A.
  
  Reduce anode current below I_H
- B.
  
  By applying negative gate pulse to G_K
- C.
  
  By applying positive gate pulse to G_A
- D.
  
  All of the above
21.

Which device is complementry SCR
- A.
  
  SUS
- B.
  
  SBS
- C.
  
  LASCR
- D.
  
  PUT
22.

Which method is more reliable & efficient to turn ON SCR
- A.
  
  Forward voltage triggering
- B.
  
  Gate triggering
- C.
  
  Dv/dt triggering
- D.
  
  Thermal triggering
23.

Reverse characteristics of SCR similer to the...
- A.
  
  TRIAC
- B.
  
  DIAC
- C.
  
  Diode
- D.
  
  UJT
24.

Device used for a chopper can be represented by
- A.
  
  Circle
- B.
  
  Square block
- C.
  
  Switch with an arrow
- D.
  
  Zig-zac
25.

In light Dimmer if Pot is in mid position then intensity of light is
- A.
  
  Medium intensity
- B.
  
  Low intensity
- C.
  
  High intensity
- D.
  
  Bulb in off condition