Basic Power Electronics (BPE)

Multiple Choice Questions

1   Which of the following is the application of Power Electronics?
    (A)   Fan Regulator
    (B)   Temperature controller
    (C)   Cycloconverter
    (D)   All the above
[showhide type=”button7c1″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: D [/showhide]
2   Which of the following is not triggering device?
    (A)   UJT
    (B)   SCR
    (C)   DIAC
    (D)   SBS
[showhide type=”button7c2″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
3   Long form of SCR is
    (A)   Silicon Conversion Rectifier
    (B)   Silicon Controlled Rectifier
    (C)   Selenium Controlled Rectifier
    (D)   None of the above
[showhide type=”button7c3″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
4   Which of the following is not Power Controlled Rectifier?
    (A)   SCR
    (B)   TRIAC
    (C)   UJT
    (D)   LASCR
[showhide type=”button7c4″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: C [/showhide]
5   SCR is a…..
    (A)   Four Layer Three Terminal Device
    (B)   Three Layer Four Terminal Device
    (C)   Four Layer Four Terminal Device
    (D)   Four Layer Two Terminal Device
[showhide type=”button7c5″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: A [/showhide]
6   TRIAC is a
    (A)   Unidirectional device
    (B)   Bidirectional Device
    (C)   Sometime Bidirectional device
    (D)   Cannot say
[showhide type=”button7c6″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
7   Which of the following is not part of VI characteristics of SCR?
    (A)   Forward Blocking state
    (B)   Forward Conduction state
    (C)   Saturation State
    (D)   Reverse Blocking State
[showhide type=”button7c7″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: C [/showhide]
8   Which of the following holds true for relationship between Holding current and Latching Current?
    (A)   Holding Current > Latching current
    (B)   Holding Current < Latching current
    (C)   Holding Current = Latching current
    (D)   Holding Current <= Latching current
[showhide type=”button7c8″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
9   As value of gate current through SCR increases
    (A)   Value of breakover voltage decreases
    (B)   Value of breakover voltage increases
    (C)   Value of breakover voltage remains unchanged
    (D)   None of the above
[showhide type=”button7c9″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: A [/showhide]
10   On state voltage drop across SCR is approximately equals to
    (A)   10 volts
    (B)   100 volts
    (C)   0.1 volt
    (D)   1 volt
[showhide type=”button7c10″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: D [/showhide]
11   Following symbol represents…

    (A)   DIAC
    (B)   TRIAC
    (C)   SCR
    (D)   UJT
[showhide type=”button7c11″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
12   Which of the following is most widely used turn on methods of SCR?
    (A)   Gate Triggering
    (B)   Light Triggering
    (C)   Forward Voltage Triggering
    (D)   dv/dt Triggering
[showhide type=”button7c12″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: A [/showhide]
13   Which of the following Thyristor can be turned on by light triggering?
    (A)   SCR
    (B)   TRIAC
    (C)   DIAC
    (D)   LASCR
[showhide type=”button7c13″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: D [/showhide]
14   Two transistor analogy of SCR can be achieved by using
    (A)   Any two-transistor choice
    (B)   Two PNP transistor
    (C)   One PNP and One NPN transistor
    (D)   One FET and One MOSFET transistor
[showhide type=”button7c14″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: C [/showhide]
15   For Protecting SCR from over voltage which of the following protection technique is used
    (A)   Snubber Circuit
    (B)   Inductor is connected in series
    (C)   Fuse is connected in series
    (D)   Heat sink
[showhide type=”button7c15″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: A [/showhide]
16   Commutation is process of
    (A)   Turning On SCR
    (B)   Turning Off SCR
    (C)   Checking SCR
    (D)   Converting SCR into TRIAC
[showhide type=”button7c16″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
17   Which of the following is not Forced Commutation?
    (A)   Class A commutation
    (B)   Class C commutation
    (C)   Class E commutation
    (D)   Class F commutation
[showhide type=”button7c17″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: C [/showhide]
18   Class C commutation is also called as
    (A)   Auxiliary Commutation
    (B)   Resonant Commutation
    (C)   Self-Commutation
    (D)   Complimentary Commutation
[showhide type=”button7c18″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: D [/showhide]
19   Following diagram represents which type of commutation

    (A)   Auxiliary Commutation
    (B)   Resonant Commutation
    (C)   Self-Commutation
    (D)   Complimentary commutation
[showhide type=”button7c19″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: A [/showhide]
20   Following symbol represents which triggering device

    (A)   UJT
    (B)   PUT
    (C)   DIAC
    (D)   SBS
[showhide type=”button7c20″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: A [/showhide]
21   In Forward blocking state, Junctions
    (A)   J1 – Forward Bias, J2-Forward Bias, J3- Forward Bias
    (B)   J1 – Forward Bias, J2-Forward Bias, J3- Reverse Bias
    (C)   J1 – Reverse Bias, J2-Forward Bias, J3- Reverse Bias
    (D)   None of the above
[showhide type=”button7c21″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: D [/showhide]
22   Role of protection circuit is
    (A)   Protect load from excess current and voltages
    (B)   Protect Source from excess current and voltages
    (C)   Protect SCR (Thyristor) from excess current and voltages
    (D)   None of the above
[showhide type=”button7c22″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: C [/showhide]
23   UJT exhibits …………………… in its characteristics
    (A)   Positive Resistance Region
    (B)   Negative Resistance Regio
    (C)   Non Ohmic Region
    (D)   Conductive Region
[showhide type=”button7c23″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
24   Long form of PUT is
    (A)   Programmable Uni Junction Transistor
    (B)   Programmable Unique Junction Thyristor
    (C)   Pointed Unit Transitory
    (D)   None of the above
[showhide type=”button7c24″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: A [/showhide]
25   Pulse duration in UJT relaxation oscillator is controlled by using
    (A)   R and C combination
    (B)   Restore Only
    (C)   Capacitor only
    (D)   By UJT
[showhide type=”button7c25″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: A [/showhide]

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