Electronics and Communication Gate 2015 Set-2 Questions with Answer

Ques 27 GATE 2015 SET-2


The value of the integral ∫−∞ 12 cos(2πt) sin(4πt)4πt dt is __________.


(3) is the correct answer.

Ques 28 GATE 2015 SET-2


If C denotes the counterclockwise unit circle, the value of the contour integral 12πjC Re{z} dz is __________.


(0.5) is the correct answer.

Ques 29 GATE 2015 SET-2


Let the random variable X represent the number of times a fair coin needs to be tossed till two consecutive heads appear for the first time. The expectation of X is __________.


(6) is the correct answer.

Ques 30 GATE 2015 SET-2


An LC tank circuit consists of an ideal capacitor C connected in parallel with a coil of inductance L having an internal resistance R. The resonant frequency of the tank circuit is

A

12π√LC

B

12π√LC√(1 − R2 CL)

C

12π√LC√(1 − LR2C)

D

12π√LC(1 − R2 CL)


(b) is the correct answer.

Ques 31 GATE 2015 SET-2


In the circuit shown, the Norton equivalent resistance (in Ω) across terminals a-b is __________.


(1.33) is the correct answer.

Ques 32 GATE 2015 SET-2


In the circuit shown, the initial voltages across the capacitors C1 and C2 are 1 V and 3 V, respectively. The switch is closed at time t=0. The total energy dissipated (in Joules) in the resistor R until steady state is reached, is __________.


(1.5) is the correct answer.

Ques 33 GATE 2015 SET-2


A DC voltage of 10 V is applied across an n-type silicon bar having a rectangular cross-section and a length of 1 cm as shown in figure. The donor doping concentration ND and the mobility of electrons μn are 1016 cm−3 and 1000 cm2 V−1 s−1 respectively. The average time (in μs) taken by the electrons to move from one end of the bar to other end is __________.


(100) is the correct answer.

Ques 34 GATE 2015 SET-2


In a MOS capacitor with an oxide layer thickness of 10 nm, the maximum depletion layer thickness is 100 nm. The permittivities of the semiconductor and the oxide layer are εs and εox respectively. Assuming εs / εox = 3, the ratio of the maximum capacitance to the minimum capacitance of this MOS capacitor is __________.


(4.33) is the correct answer.

Ques 35 GATE 2015 SET-2


The energy band diagram and the electron density profile n(x) in a semiconductor are shown in the figures. Assume that n(x) = 1015 e(qαx / kT) cm−3, with α = 0.1 V/cm and x expressed in cm. Given Dn = 36 cm2s−1, and kTq = 0.026 V, Dμ = kTq. The electron current density (in A/cm2) at x=0 is

A

−4.4 × 10−2

B

−2.2 × 10−2

C

0

D

2.2 × 10−2


(c) is the correct answer.

Ques 36 GATE 2015 SET-2


A function of Boolean variables X, Y and Z is expressed in terms of the min-terms as F(X,Y,Z) = ∑(1,2,5,6,7). Which one of the product of sums given below is equal to the function F(X,Y,Z)?

A

(A) (X+Y+Z) · (X+Y+Z) · (X+Y+Z)

B

(B) (X+Y+Z) · (X+Y+Z) · (X+Y+Z)

C

(C) (X+Y+Z) · (X+Y+Z) · (X+Y+Z) · (X+Y+Z) · (X+Y+Z)

D

(D) (X+Y+Z) · (X+Y+Z) · (X+Y+Z) · (X+Y+Z) · (X+Y+Z)


(b) is the correct answer.

Ques 37 GATE 2015 SET-2


The figure shows a binary counter with synchronous clear input. With the decoding logic shown, the counter works as a

A

mod-2 counter

B

mod-4 counter

C

mod-5 counter

D

mod-6 counter


(d) is the correct answer.

Ques 38 GATE 2015 SET-2


A 1-to-8 demultiplexer with data input Din, address inputs S0, S1, S2 (with S0 as the LSB) and Y0 to Y7 as the eight demultiplexed outputs, is to be designed using two 2-to-4 decoders (with enable input E and address inputs A0 and A1) as shown in the figure. Din, S0, S1 and S2 are to be connected to P, Q, R and S, but not necessarily in this order. The respective input connections to P, Q, R, and S terminals should be

A

S2, Din, S0, S1

B

S1, Din, S0, S2

C

Din, S0, S1, S2

D

Din, S2, S0, S1


(d) is the correct answer.

Ques 39 GATE 2015 SET-2


The diode in the circuit given below has VON = 0.7 V but is ideal otherwise. The current (in mA) in the 4 kΩ resistor is __________.


(0.6) is the correct answer.

Unique Visitor Count

Total Unique Visitors

Loading......