EE MCQ

SSC JE Electrical 2019 with solution SET-1
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Two coupled coils with L1 = L2 = 0.5H have a coupling coefficient of K = 0.75. The turn ratio N1 ⁄ N2 = ?

The self-inductance is given as

L = μN2A/I

L ∝ N2

where

N is the number of turns of the solenoid

A is the area of each turn of the coil

l is the length of the solenoid

and μ is the permeability constant

L1/L2 = N21/N22

0.5/0.5 = N21/N22

N1/N2 = 1

Related Question

SSC JE Electrical 2019 with solution SET-1
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With the current direction marked in the circuit shown, the net voltage applied is

Net voltage = −V2 + V1

Net voltage = −(V2 − V1)

SSC JE Electrical 2019 with solution SET-1
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4F2D is a/an number

The hexadecimal number system is also called base-16, a numeration system in which all numbers are represented using the symbols 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, and F only. The system is base of 16. The hexadecimal numbers are used to represent binary numbers because of ease of conversion and compactness.

SSC JE Electrical 2019 with solution SET-1
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Which of the following plants experiences chain reactions?

A nuclear power plant is a steam turbine plant where steam is generated by a nuclear reactor. Nuclear energy is the energy that is trapped inside each atom. Nuclear energy is obtained by fission of uranium-plutonium or thorium or the fusion of hydrogen into helium.

In normal conditions, the energy released due to the disintegration of a uranium atom is significantly low. The capturing of neutrons by the uranium-235 is rather easy and to fission it for the release of the energy. In a chain reaction, particles released by the splitting of the atom strike other uranium atoms and split them. The particles released by this further split other atoms in a chain process. The chain reaction gives off heat energy. This heat energy is used to boil heavy water at the core of the reactor.

SSC JE Electrical 2019 with solution SET-1
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Let T be the net torque developed by the rotor runs at ω rad/s. What is the mechanical power developed?

By the term, torque is meant the turning or twisting moment of a force about an axis. It is measured by the product of the force and the radius at which this force acts. Consider a pulley of radius r meter acted upon by a circumferential force of F Newton which causes it to rotate at N r.p.m.

The angular speed of the pulley is

ω = 2πN/60 rad/sec

Work is done by this force in one revolution

= Force × distance = F × 2πR Joule

The power developed = Work Done/Time

= (F × 2πR)/60/N

= (F × R) × (2πN)/60

The power developed = T × ω watt or P = T ω Watt

pmech = (ωT)

SSC JE Electrical 2019 with solution SET-1
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For a three-layer stranded wire, the number of strands in the first, second, and third layer respectively are:

The total number of the conductor in stranded cable is given by

N = 3x2 − 3x + 1

Where

x = no. of layer

For layer 1

N1 = 3(1)2 − 3(1) + 1

N1 = 1

For layer 2

N2 = 3(2)2 − 3(2) + 1

N2 = 7

In layer 2 no. of conductor = N2 − N1 = 7 − 1 = 6

For layer 3

N3 = 3(3)2 − 3(3) + 1

N3 = 19

In layer 3 no. of conductor = N3 − N2 = 19 − 7 = 12