GATE 2020: Toppers Quiz 12 (App update required to attempt this test) for ESE & GATE EE Exams

Question 1

Consider the circuit shown below. Find the current 'I' through the 24 Ω resistor and the power loss in the 24 Ω resistor.

Question 2

Consider the following discrete system where x(n)={1,1,1} for n=0,1,2.

The same input is applied to another system shown below and the output obtained is the same. The impulse response of A and B will be

Question 3

An ac induction motor is used to for speed control application. It is driven from an inverter with a constant V/f control. The motor nameplate details are-

V=415V

Ph=3

f=50Hz

N=2800rpm

if motor is run with the inverter output frequency set at 40Hz, and with half the rated slip. The running speed of the motor is-

Question 4

A separately excited dc motor runs at 1000 rpm from a 200 V dc supply. The motor is fed from a single phase fully controlled bridge converter with a firing angle of 60° and 230V, 50 Hz source. Armature resistance is assumed to be neglected. The speed of motor will be.

Question 5

A moving coil instrument has a resistance of 3 Ω and gives a full scale deflection of 8 mv. Show how the instrument may be used to measure voltage up to 30 v and current up to 8A.

Question 6

An alternator delivers 1pu power operating at 50 Hz to an infinite bus through a transmission circuit having negligible resistance. A fault occurs reducing the maximum power transferrable to 0.75pu. Before the occurrence of fault the power was 2pu and after the fault clearance it is 1.25pu. Find the critical clearing angle in degree?

Question 7

A 3-phase transmission line is shown in the figure:

Voltage drop across the transmission line is given by the following equation:

Shunt capacitance of the line can be neglected. If the line has positive sequence impedance of 15Ω and zero sequence impedance of 48Ω, then the values of Z_s and Z_m will be

Question 8

A 20 kVA single phase transformer has iron loss of 250 W and full load Cu loss of 500 W respectively. If the maximum efficiency occurs at 85% of full load, the new iron loss(W’) and Cu loss(W’’) under the full load operation assuming that full load loss is constant will be

Question 9

A 4-bit serial-in-parallel-out shift register is used with a feedback as shown in figure. The shifting sequence is Q_A→Q_B→Q_C→Q_D

If the output is 0000 initially, the output repeats after

Question 10

A separately excited d.c. motor is to be controlled from a single-phase half-controlled bridge at a speed of 1500 r.p.m. The motor is fed from an ac source of 230 V at 50 Hz. The motor has a back emf of 80 V and the armature has a resistance of 5Ω. The SCRs are fired symmetrical at α = 30° in every half cycle. The value of average armature current(in A) is

Question 11

Given the magnetic vector potential

wb/m. Calculate the total magnetic flux crossing the surface

1 < ρ < 2 m and 0 < z < 5 m

Question 12

A 3-østar connected 400V synchronous motor takes a power input pf 5472 Watts at rated voltage. Its synchronous reactance is 10 per phase and resistance is negligible.If its excitation voltage is adjusted equal to the rated voltage of 400V,power factor of the motor is ?

Question 13

The divide by N counter is shown below. If initially Q₀ = 0, Q₁ = 1, Q₂ = 0 the value of N is _______.