Time Left - 45:00 mins

GATE 2020: Toppers Quiz 21 (App update required to attempt this test)

Attempt now to get your rank among 246 students!

Question 1

16’s complement of BABA is

Question 2

A generator of 200MVA rating has an inertia constant of 10MJ/MVA. With the same rotor, if the rating is changed to 400MVA, then the inertia constant (in MJ/MVA) becomes

Question 3

A 200 V d.c. series motor develops its rated output at 1500 rpm while taking 20 A. Armature and series field resistances are 0.6 Ω and 0.4 Ω respectively. To obtain rated torque at 1000 rpm, external resistance (in Ω) must be added is

Question 4

A thyristor is used in an application carrying half sinusoidal current of period 2 msec and a peak of 50 A as shown in figure. The thyristor may model during conduction to have a constant voltage drop of 1.2 V and a dynamic resistance of 5 mΩ. Calculate the average conduction loss in the device?

Question 5

The asymptotic Bode magnitude plot of a lead network with its pole and zero on left half of the s-plane is shown in figure. The frequency at which the phase angle of the network is maximum (in rad/sec) is

Question 6

A 25 MVA, 11 kV generator has

its negative and zero sequence reactances are respectively 0.3 and 0.1 pu. The neutral of generator is solidly grounded. If the fault occurred in line to line on b and c phases, then line to line voltage V_ab is.

Question 7

A 4 pole DC generator lap wounded has 240 coils of 2 turns each. Resistance of one turn is given as 0.05 ohm. Length and diameter of armature coil are 50cm and 40 cm respectively. Each pole subtends 60⁰ mechanical angle. Air gap flux density is uniform over pole shoe measured as 0.4 T. Rated speed of DC generator is given as 1200 rpm. If rated armature current is given as 20 A, What will be the terminal voltage (in volt) of DC machine?

Question 8

In a CE unbypass amplifier, the voltage gain Av is given by

Question 9

In the circuit shown below

The maximum value of average current rating for the thyristor in case load current remains constant is

Question 10

The input

and impulse response

is given by

and

. Then the output y[n] at n = 0 will be

Question 11

Determine the number of turns per phase in each winding(T_ph1 andT_ph2) of a 3-phase transformer with a ratio of 20000/2000 V at 50 Hz. The high voltage winding is delta connected and the low voltage winding is star connected. Each core has a cross section area of 500 cm² . Assume a flux density of about 1.2 Wb/m² .

Question 12

In the figure, two voltage sources act on the load impedance connected to the terminal A and B. If the load is variable in both reactance and resistance, for what load, Z_L will receive maximum power?

Question 13

In a circuit of single phase induction energy meter, the pressure coil current lags the voltage by 88 , the errors while measuring power in two circuits having power factors unity and 0.5 lagging respectively

Question 14

Find the magnitude of the electric field intensity in V/m at the origin due to an 8nC charge located at (2, –3, 1).

Question 15

A 220 V, 50 Hz, 6-pole, single-phase induction motor has the following circuit model.

The rotational losses of the motor are estimated to be 75 W. At a motor speed of 940 rpm, _________ A is the magnitude of line current.

Question 16

In a 132 kV system, the series inductance up to the point of circuit breaker location is 50 mH. The shunt capacitance at the circuit breaker terminal is 0.05 μF. The critical value of resistance in ohms required to be connected across the circuit breaker contacts which will give no transient oscillation is _____________.

Question 17

If the load voltage V_L is 12V when a 10ohm resistance is connected across the load terminals of a linear network and V_L is 24V when 30ohms is connected.Find the Thevenin’s equivalent resistance for the above mentioned linear network characteristics.

Question 18

A chopper circuit shown below has input dc voltage of 200 V and a load of R = 10 Ω in series with an inductor of L = 80 mH. If load current varies linearly between 12 A and 16 A, then time ratio for this chopper is ---------.

Question 19

Two long overhead transmission lines A and B having surge impedence of 450Ω and 430Ω respectively are connected by a short underground cable C of surge impedence 60Ω. A rectangular surge of 100kV and of infinite length travels along A towards the cable C Find the sum of the reflection coefficient at junction BC and refracted voltage at junction A, C …………..

Question 20

A single phase full bridge rectifier is connected to the R load and operated at firing angle α=90⁰. The output voltage from the rectifier is fed to the DC boost converter whose output voltage is 220V and operated at discontinuous conduction mode with duty ratio D= 0.4 ,switching frequency f=20kHz which is shown in below figure. Then the time at which inductor current becomes zero (in µseconds)

246 attempts
0 upvotes
1 comment

Tags :

ESE & GATE EE General

Jan 26ESE & GATE EE