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GATE 2014 EE (EE2) – Question 61

Analog and Digital Electronics · VCOs and timers, combinatorial and sequential logic circuits, multiplexers, demultiplexers · 2 marks · Multiple choice

Which implements a JK flip-flop using a T flip-flop?

Diagram for GATE 2014 EE (EE2) question 61
  1. Circuit A
  2. Circuit B
  3. Circuit C
  4. Circuit D

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Show answer and explanation

Correct answer: (B) Circuit B

Explanation

A Tflip-flop obeysQnext=T xor Q. Matching the JKnext-state relation gives T=JQbar+KQ. OptionBforms T=(J+Q)(K+Qbar)=JK+JQbar+KQ;the consensus termJKis redundant,so it is equivalent. Hence **B**. Tracking which output is fed to each ORgate is essential.