Multiple choice

A gate having two inputs (A and B) and one output (Y) is implemented using a 4-to-1 multiplexer as shown in the figure below. A1 (MSB) and A0 are the control bits and I0 - I3 are the inputs to the multiplexer. The gate is

  1. NAND

  2. NOR

  3. XOR

  4. OR

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A1 = A, A0 = B, I0 = I2 = A, I1 = I3 = BY = $\bar A_1$$\bar A_0$I0 + $\bar A_1$A0 I1 + A1$\bar A_0$I2 + A1 A0 I3Y = $\bar A$$\bar B$A + $\bar A$BB + A$\bar B$A + ABBY = $\bar A$B + A$\bar B$ + AB = $\bar A$B + A = A + B