Electronics and Communication Gate 2016 Set-2 Questions with Answer

Ques 27 GATE 2016 SET-2

The figure shows a half-wave rectifier with a 475 μF filter capacitor. The load draws a constant current I₀=1 A from the rectifier. The figure also shows the input voltage V_i, the output voltage V_C and the peak-to-peak voltage ripple u on V_C. The input voltage V_i is a triangle-wave with an amplitude of 10 V and a period of 1 ms. The value of the ripple u (in volts) is

Ques 28 GATE 2016 SET-2

In the opamp circuit shown, the Zener diodes Z1 and Z2 clamp the output voltage V₀ to +5 V or -5 V. The switch S is initially closed and is opened at time t=0. The time t=t₁ (in seconds) at which V₀ changes state is

Ques 29 GATE 2016 SET-2

An opamp has a finite open loop voltage gain of 100. Its input offset voltage V_ios(=+5mV) is modeled as shown in the circuit below. The amplifier is ideal in all other respects. V_input is 25 mV.

Ques 30 GATE 2016 SET-2

The Ebers-Moll model of a BJT is valid

Ques 31 GATE 2016 SET-2

A long-channel NMOS transistor is biased in the linear region with V_DS=50 mV and is used as a resistance. Which one of the following statements is NOT correct?

Ques 32 GATE 2016 SET-2

A voltage V_G is applied across a MOS capacitor with metal gate and p-type silicon substrate at T=300 K. The inversion carrier density (in number of carriers per unit area) for V_G=0.8 V is 2×10¹¹cm^-2. For V_G=1.3 V the inversion carrier density is 4×10¹¹cm^-2. What is the value of the inversion carrier density for V_G=1.8 V?

Ques 33 GATE 2016 SET-2

Consider avalanche breakdown in a silicon p⁺n junction. The n-region is uniformly doped with a donor density N_D. Assume that breakdown occurs when the magnitude of the electric field at any point in the device becomes equal to the critical field E_crit. Assume E_crit to be independent of N_D. If the built-in voltage of the p⁺n junction is much smaller than the breakdown voltage, V_BR, the relationship between V_BR and N_D is given by

Ques 34 GATE 2016 SET-2

Consider a region of silicon devoid of electrons and holes, with an ionized donor density of N_d⁺=10¹⁷cm^-3. The electric field at x=0 is 0 V/cm and the electric field at x=L is 50 kV/cm in the positive x direction. Assume that the electric field is zero in the y and z directions at all points.

Ques 35 GATE 2016 SET-2

Consider a long-channel NMOS transistor with source and body connected together. Assume that the electron mobility is independent of V_GS and V_DS. Given, g_m=0.5 μA/V for V_DS=50 mV and V_GS=2 V and g_d=8 μA/V for V_GS=2 V and V_DS=0 V, where g_m=∂I_D/∂v_GS and g_d=∂I_D/∂v_DS. The threshold voltage (in volts) of the transistor is ___________.

Ques 36 GATE 2016 SET-2

The value of x for which the matrix

Ques 37 GATE 2016 SET-2

Consider the complex valued function f(z)=2z³+b|z|³ where z is a complex variable. The value of b for which the function f(z) is analytic is

Ques 38 GATE 2016 SET-2

As x varies from -1 to +3, which one of the following describes the behaviour of the function f(x)=x³-3x²+1?

Ques 39 GATE 2016 SET-2

How many distinct values of x satisfy the equation sin(x)=x/2 where x is in radians?