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SCR Protection MCQs

Practice SCR Protection MCQs with four options, answers and explanations for focused Electronics & Telecommunication Engineering revision.

Question 1
Power ElectronicsSCR Protection

A high rate of rise of forward voltage across an OFF SCR may cause unwanted turn-on due to?

  • AJunction capacitance current
  • BHolding current becoming zero
  • CLoad resistance becoming infinite
  • DGate resistance alone
Report an error
Correct Answer: A. Junction capacitance current
Explanation: Internal junction capacitances carry i=C dv/dt; excessive dv/dt can create sufficient internal current to trigger the SCR.
Reference: Standard power electronics: scr protection
Question 2
Power ElectronicsSCR Protection

A snubber circuit connected across an SCR is commonly used to limit?

  • Adv/dt
  • BLoad frequency to zero
  • CGate current to exactly zero
  • DDC output power
Report an error
Correct Answer: A. dv/dt
Explanation: An RC snubber reduces the rate of rise of voltage across the SCR and helps prevent false triggering.
Reference: Standard power electronics: scr protection
Question 3
Power ElectronicsSCR Protection

A small series inductor is often used with an SCR to limit excessive?

  • Adi/dt during turn-on
  • Bdv/dt in the OFF state only
  • CHolding current
  • DGate voltage ripple only
Report an error
Correct Answer: A. di/dt during turn-on
Explanation: An inductor opposes rapid current change and can keep SCR turn-on di/dt within its safe rating.
Reference: Standard power electronics: scr protection