Question

A person applies a sine wave and square wave to an $AND$ gate as shown in the figure (i) and (ii). Assuming that both the voltages are applied in phase, the person observes the output at $E$ and $F$ on (i) and (ii), respectively. [Assume minimum voltage of $5\, V$ is equivalent to logic (i)]

• A. Square wave at 50 Hz and square wave at 100 Hz.
• B. Sine wave at 50 Hz and square wave at 100 Hz.
• C. No output and sine wave at 100 Hz.
• D. No output and pulsed wave at 100 Hz.

Answer 1

Answer: (C)

Given,
(i) Sine wave, $50 \,Hz , 2 \,V$

square wave $107\, Hz , 6\, V$
(ii) Sine wave, $100\, Hz , 8\, V$

square wave $100 \,Hz , 6\, V$
In figure (i), sine wave and square wave both have different frequency, respectively, $50\, Hz$ and $107 \,Hz$. Hence, these voltages are not processed by $AND$ gate, therefore, no output is obtained from gate (i). In figure (ii), since wave and square wave both have same frequency of $100 \,Hz$, hence, these voltage are processed by $AND$ gate. Since, logic gate ($AND$ gate) gives output in two level $(0$ and $1)$ only at same frequency of input. Therefore, the output of gate (ii) will be pulsed wave of $100\, Hz$.