GATE EC 2021: Semi Syllabus Quiz 1 (App update required to attempt this test) for ESE & GATE EC Exams

Question 1

Consider the diode circuit shown in the figure below:

If the diode are ideal and the input voltage is a 1 kHz sine wave with a peak voltage of 10V, then the output waveform can be represented as

Question 2

Find the overall transfer function of the control system whose signal flow graph is shown in figure below.

Question 3

In the circuit shown in figure, voltage V₀ is

Question 4

The open loop transfer function of a system with unity negative feedback system is given by

For K=2, the nyquist plot of G(s) encircles the point (-1+j0)

Question 5

For the given circuit determine the coefficient of coupling k, for series resonance condition.

Question 6

In a silicon semiconductor material at T = 300 K, the doping concentrations are N_d = 10¹⁵ cm^-3 and N_a = 0. The equilibrium recombination rate is R_p0 = 10¹¹ cm^-3 –s^-1. A uniform generation rate produces an excess-carrier concentration of δn = δp = 10¹⁴ cm^-3.

By _ _ _ _ _× 10⁹ factor does the total recombination rate increase ?

Question 7

If the op-amp in the circuit shown in figure below is ideal then the value of current supplied by the 15 V supply is (Assume β of the transistor to be very large).

Question 8

Find the equivalent resistance across terminals A and B i.e. R_AB in ohms?

Question 9

The neutral base width of a bipolar transistor, biased in the active region, is 0.5 μm. the maximum electron concentration and the diffusion constant in the base are 10¹⁴/cm³ and D_n = 25 cm²/sec respectively. Assuming negligible recombination I the base, the collector current density is (the electron charge is 1.6 × 10^–19 coulomb)

Question 10

Find the ABCD parameter matrix for the given circuit

Question 11

In the voltage doubler circuit shown in the figure, the switch ‘S’ is closed at t = 0. Assuming diodes D₁ and D₂ to be ideal, load resistance to be infinite and initial capacitor voltages to be zero. The steady state voltage across capacitor C₁ and C₂ will be

Question 12

In the series voltage regulator circuit shown below V_BE = 0.7 V, β = 50, V_Z = 8.3 V. The output voltage V₀ is _____ volts.

Question 13

The parameters in the base region of an npn bipolar transistor are D_n = 20 cm²/s, n_B0 = 10⁴ cm^-3, x_B = 1 μm, A_BE = 10^-4 cm². What will be the collector current (in μA) for VBE = 0.5 V?

Question 14

In the circuit shown in figure below, what is the value of R_L such that maximum power is transferred to the load?

Question 15

The OP Amp circuit shown in figure is

Question 16

Calculate Z₁₁ (in Ω) parameter for the given network.

Question 17

Find the output voltage of the following circuit assume the ideal op-amp behavior.

______ V.

Question 18

Direction: Consider the impurity doping profile in a silicon pn junction as shown in figure. Assume that zero voltage is applied to the pn junction. (For Si, relative permittivity is ϵ_r = 11.7)

What will be the distances x_n and x_p that the space charge region extends into the n and p-regions respectively (in μm)?

Question 19

Find the current in 4Ω resistor?

Question 20

In a silicon semiconductor material at T = 300 K, the doping concentrations are N_d = 10¹⁵ cm^-3 and N_a = 0. The equilibrium recombination rate is R_p0 = 10¹¹ cm^-3 –s^-1. A uniform generation rate produces an excess-carrier concentration of δn = δp = 10¹⁴ cm^-3.

The excess-carrier lifetime is _ _ _ _ _× 10^-7 s.

Question 21

A system is shown in below.

If R(s) is unit impulse input, the rise time and settling time for this system is

Question 22

Given astable multivibrator generate sq wave of 10 kHz with 60% duty cycle. It uses a capacitor of 500 pF. Find the value of R₁ of R₂

Question 23

Direction: Consider the impurity doping profile in a silicon pn junction as shown in figure. Assume that zero voltage is applied to the pn junction. (For Si, relative permittivity is ϵ_r = 11.7)

The built-in potential barrier, V_bi, is

Question 24

Find the value of current I_x in the following circuit is (in Ampere) ______.

Question 25

The switch S in the circuit of figure has been closed for a long time and is opened at t = 0. The current i(t) for t > 0 is