ugc net 2018 july -92

Question

In RS flip flop, the output of the flip flop at time (t+1) is same as the output at time t, after the occurrence of a clock pulse if 

1. S=R=1
2. S=0,R=1
3. S=1, R=0
4. S=R=0

Comments

output of the flip flop at time (t+1) is same as the output at time t, after the occurrence of a clock pulse that means previous o/p is reflecting as present o/p.

this is possible when S=R=0.

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i mark this option but dout on first option

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in S-R flipflop S=R=1  is a invalid combination