GATE | Gate IT 2005 | Question 46
A line L in a circuit is said to have a stuck-at-0 fault if the line permanently has a logic value 0. Similarly a line L in a circuit is said to have a stuck-at-1 fault if the line permanently has a logic value 1. A circuit is said to have a multiple stuck-at fault if one or more lines have stuck at faults. The total number of distinct multiple stuck-at faults possible in a circuit with N lines is
(B) 3^N – 1
(C) 2^N – 1
In a line, there can be three possibilities :
1. Stuck-at 0 fault
2. Stuck-at 1 fault
3. No fault
Thus, total combinations = 3N
It is mentioned that one or more lines have stuck at faults.
So, a case in which there is no fault in any line i.e. all lines are correct can not occur.
Total combinations = 3N – 1
Thus, option (B) is correct.
Please comment below if you find anything wrong in the above post.
Attention reader! Don’t stop learning now. Practice GATE exam well before the actual exam with the subject-wise and overall quizzes available in GATE Test Series Course.
Learn all GATE CS concepts with Free Live Classes on our youtube channel.