1
GATE ECE 2026
MCQ (Single Correct Answer)
+2
-0.67

A Boolean function, $f(x, y, z)$ with $x$ as MSB and $z$ as LSB is realized by $4: 1$ multiplexer (MUX) with select lines, $S_1$ and $S_0$ ( $S_1$ is MSB, $S_0$ is LSB) and inputs, $I_0, I_1, I_2, I_3$ as shown in the Figure.

Which of the following options is the correct expression of $f(x, y, z)$ ?

GATE ECE 2026 Digital Circuits - Combinational Circuits Question 1 English
A

$x z+y$

B

$x \bar{y}+z$

C

$x y+\bar{z}$

D

$\bar{x} y+\bar{z}$

2
GATE ECE 2026
MCQ (Single Correct Answer)
+2
-0.67

A shift-left Shift Register (SR) and a $D$ flip-flop are connected to a synchronized clock as shown in the Figure. Assume that the SR and D flip-flops are initially cleared and the XOR gate has no propagation delay.

Which of the following options gives the correct binary representation $\left(b_7 b_6 b_5 b_4 b_3 b_2 b_1 b_0\right)$ of the content of the shift register immediately after the $5^{\text {th }}$ clock transition (positive edge)?

GATE ECE 2026 Digital Circuits - Sequential Circuits Question 1 English

A

00011111

B

10111111

C

00111111

D

11000011

3
GATE ECE 2026
MCQ (More than One Correct Answer)
+2
-0.67

Consider the four-variable Boolean function, $f(w, x, y, z)=\Sigma m(0,2,5,7,8,10,13,14,15)$ with ' $w$ ' as MSB and ' $z$ ' as LSB. Which of the following expressions is/are the valid form(s) of $f(w, x, y, z)$ ?

A

$\bar{x} \bar{z}+x z+w x y$

B

$x z+w x y+w \bar{x} \bar{z}+\bar{w} x y \bar{z}$

C

$\bar{x} \bar{z}+w x y+w \bar{x} \bar{z}+\bar{w} x y \bar{z}$

D

$\bar{x} \bar{z}+x z+w y \bar{z}$

4
GATE ECE 2026
MCQ (Single Correct Answer)
+1
-0.33

Consider the Friis' transmission equation $P_R=\left(P_T G_T G_R \lambda^2\right) /(4 \pi D)^2$, where $P_R$ and $P_T$ are the received and the transmitted powers, respectively.

$G_T$ and $G_R$ are the gain of transmitting and receiving antennas, respectively, $D$ is the distance between the transmitting and receiving antennas, and $\lambda$ is the wavelength in free space.

Given: $G_T=G_R=1.0, \lambda=0.30 \mathrm{~m}$ and $P_T=+10 \mathrm{dBm}$.

Choose the distance (D), in km , from the following options at which the received power, $P_R=-90 \mathrm{dBm}$ ?

A

$\frac{15}{4 \pi}$

B

$\frac{15}{2 \pi}$

C

$\frac{75}{2 \pi}$

D

$\frac{3}{4 \pi}$