Q141 / 160 · AP EAMCET 2020 (22 Sep Shift 2) · Physics
The two combinations of NAND gates shown in the figure are equivalent to
(i) 
(ii)
(ii)
- Correct answerA(i)-Or gate, (ii)-AND gate
- B(i)-AND gate, (ii)-NOT gate
- C(i)-NOT gate, (ii)-AND gate
- D(i)-AND gate, (ii)-OR gate
Solution
The output of combination of NAND gate shown in circuit diagram (i) is given as
$$ \begin{aligned} & C=\overline{\bar{A} \cdot \bar{B}}=\overline{\bar{A}}+\overline{\bar{B}} \quad[\because \overline{x \cdot y}=\bar{x}+\bar{y}] \\ & C=A+B=\text { Output of OR gate } \end{aligned} $$ The output of combination of NAND gate shown in circuit diagram (ii) is given as Fig. (ii) $C=\overline{\overline{A B}}=A B=$ Output of AND gate
$$ \begin{aligned} & C=\overline{\bar{A} \cdot \bar{B}}=\overline{\bar{A}}+\overline{\bar{B}} \quad[\because \overline{x \cdot y}=\bar{x}+\bar{y}] \\ & C=A+B=\text { Output of OR gate } \end{aligned} $$ The output of combination of NAND gate shown in circuit diagram (ii) is given as Fig. (ii) $C=\overline{\overline{A B}}=A B=$ Output of AND gate
Hence, the correct answer is option: 'A'.