For a NAND gate, struck-at 1 fault in second input line cannot be detected if
A)q is 1
B)q is 0
C)q changes from 1 to 0
D)q changes from 0 to 1

Question

Quizplus · Accepted Answer

A NAND gate with a stuck-at 1 fault in the second input line will always produce a 1 output if the other input is 1, regardless of the actual input on the faulty line. Therefore, when the expected output q is 0, this fault cannot be detected because the NAND gate's output would incorrectly remain 1 due to the fault, making it impossible to distinguish from a correct operation in this scenario.

For a NAND Gate, Struck-At 1 Fault in Second Input