GATE 2020: Toppers Quiz 16 (App update required to attempt this test) for ESE & GATE EE Exams

Question 1

The frequency at the output of the following cascaded circuit is …………. Hz.

Question 2

Which of the following statements is/are true?
1) If the firing angle delay α value is large then the performance of a phase controlled converter reduces.
2) The output voltage is low for large values of firing angle delay.

Question 3

For given OCC of DC shunt generator the value critical speed for voltage building will be__. For voltage build up process to occur the speed of the generator should be__ than critical speed.
(given rated speed= 1700rpm)

Question 4

The distribution system shown in the figure is to be protected by over current system of protection. For proper fault discrimination, directional over current relays will be required at locations .

Question 5

An incandescent lamp is marked 40 W, 240V. If resistance at room temperature (26 °C) is 120Ω, and temperature coefficient of resistance is 4.5 × 10^–3/ °C, then its 'ON' state filament temperature in °C is approximately_____

Question 6

A fuse wire of circular cross section has a radius of 0.8 mm. The wire blows off at a current of 8A. The radius of the wire that will blow off at a current of 1 A is ________ mm.

Question 7

Find the transfer function

relating displacements y and x for the mechanical system of given figure.

Question 8

A star connected synchronous motor at 100 kVA, 3-φ, 1400V, 23A, 60Hz, 126.5 rpm has an effective resistance of 0.5 ohm and a synchronous reactance of 10 ohm per phase. Determine internal power developed by the motor when it is operating at rated current and 0.5 power factor leading.

Question 9

Find the value of RB to design a second order butter worth voltage control voltage source band worth filter with

and gain at central frequency is 10 and given R =1k and Ra=1k?

Question 10

Below figure shows a full bridge inverter, employed for sinusoidal bipolar pulse width modulation.

Given below shows the sinusoidal wave as the reference and triangular wave as the carrier, and their corresponding output voltage. Which of the following pair of switches are on, when the instantaneous value of the sine reference is less than that of the triangular carrier.

Question 11

Calculate the maximum charge per unit area which can be induced in the semicoductor material. If 3

atoms are present per square meter in the first layer of the silicon crystal, what proportion can be ionized by applying a one sixth of voltage to gate, of break down voltage?
(Silicon dioxide has permeability of 3.85, inuslating layer thickness = 0.1

)

Question 12

In a 25kVA, 2000/200V transformer the iron and full load copper losses are 350W and 400W respectively. Calculate the value of maximum efficiency.

Question 13

Find the Fourier series coefficient C_n of the given waveform below?

Question 14

A sheet of Bakelite 4.5 mm thick is tested at 50Hz between electrode 0.12 m in diameter. The Schering bridge employs a standard air capacitor C₂ of 106pF capacitance a non reactive resistance R₄ of

in parallel with a variable capacitor C₄ and a non reactive variable resistance R₃ balance is obtained with C₄ = 0.5μF and R₂ = 260Ω.

Then the relative permittivity of sheet is _______ if permittivity of free space is = 8.84 × 10^-¹² F/m.

Question 15

An amplifier has a voltage amplification Av and a fraction mv of its output is feedback in opposition to the input. If mv = 0.1 and Aν = 100, calculate the percentage change in the gain of the system if Aν falls 6 db due to ageing.

Question 16

The pole zero plot of the impulse response of a discrete system is shown below.

An input of x(n)= cos (pi/4)n + j sin (pi/4)n is applied to the system. The output of the system will be

Question 17

A 100 kVA transformer has 90% efficiency at half load 0.8 pf lagging and 92% at full load unity pf. Then what is the maximum efficiency (in %) at unity power factor load –

Question 18

The voltage gain A, of the circuit shown in below is

Question 19

Determine the current flowing in the ammeter having 1 ohm internal resistance connected in a series with a 3Ω’s resistors as shown in figure?

Question 20

A 250V M.I. voltmeter has coil resistance of 500Ω, coil inductance 0f 1.04 H and series resistance of 2kΩ. The meter reads correctively at 250V D.C. What will be the value of capacitance to be used for shunting the series resistance to make the meter read correctly at 50HZ? What is the reading of voltmeter(in Volts) on A.C. without capacitance?