Physics - Semiconductors Question with Solution | TestHub

Lower NOT gate inverts input to zero. NOT gate from NAND gate inverts this output to$1$and upper NAND gate converts this input$1$and input$0$to$1$.

Thus$\mathrm{A}=1$and$\mathrm{B}=1$become inputs of NAND gate giving final output as zero. Choice A is correct.