Question

JEE MAINS PHYSICS QUESTION SEPTEMBER 2020

Answer 1

Answer :

Boolean expression for NOT gate :

• $\bf{Y=\bar{A}}$

Boolean expression for NAND gate :

• $\bf{Y=\overline{A\ast B}}$

◈ Time ➝ 0 to 5 :

Input A = 0

Output A = $\bar{0}$ = 1

Input B = 1

Output B = $\bar{1}$ = 0

Final output Y = $\sf{\overline{1\ast 0}}$ = 1

◈ Time ➝ 5 to 10 :

Input A = 1

Output A = $\bar{1}$ = 0

Input B = 0

Output B = $\bar{0}$ = 1

Final output Y = $\sf{\overline{0\ast 1}}$ = 1

◈ Time ➝ 10 to 15 :

Input A = 0

Output A = $\bar{0}$ = 1

Input B = 0

Output B = $\bar{0}$ = 1

Final output Y = $\sf{\overline{1\ast 1}}$ = 0

◈ Time ➝ 15 to 20 :

Input A = 1

Output A = $\bar{1}$ = 0

Input B = 1

Output B = $\bar{1}$ = 0

Final output Y = $\sf{\overline{0\ast 0}}$ = 1

Hence, (c) is the correct answer!