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SSC JE Electrical 2019 with solution SET-2
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Both the main winding and auxiliary winding of a single-phase induction motor is placed on the ______?

A single-phase induction motor with only one winding on the stator cannot produce any starting torque. Hence, some extra arrangement is required to start the motor. In the running condition, the motor is capable of developing the torque with only one winding on the stator.

The simplest method of starting is to provide an auxiliary winding on the stator in addition to the main winding. The two windings are placed in the stator with their axes displaced by 90 electrical degrees in space.

SSC JE Electrical 2019 with solution SET-2
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In an alternator, if α = 60°, then find the pitch factor?

The factor by which, the induced E.M.F gets reduced due to short pitching is called pitch factor or coil span factor denoted by Kc. It is given as

Kc = cosα/2

given

α = 60°

Kc = cos60/2

Kc = cos30°

Kc = √3/2

SSC JE Electrical 2019 with solution SET-2
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The 2’s complement of 1010101 is

The 2’s complement of the number (1010101)2 is found in two steps. First, convert the given number into its l’s complement.

1’s complement of a binary number is just an inversion of individual bits.

1’s complement of (1010101)2 is (0101010)2

To find 2’s complement of the number add one to the least significant bit (LSB). So

SSC JE Electrical 2019 with solution SET-2
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In the salient pole of the phase synchronous machine, the rotor will have

The rotor of the synchronous machine carries a field winding that is supplied with d.c. through two slip rings by a separate d.c. source. Synchronous Rotor construction is of two types, namely :

Salient (or projections) pole type.

Cylindrical type (or non-salient pole type)**Salient-pole rotor:**-

In this type, salient poles are mounted on a large circular steel frame which is fixed to the shaft of the alternator.

The rotors of salient-pole rotor machines have concentrated winding on the poles and a nonuniform air gap.

Salient pole generators have a large number of poles. sometimes as many as 50, and operate at lower speeds.

The synchronous generators in hydroelectric power stations are of the salient pole type and are driven by water turbines.

The rotors are shorter axial length but have a large diameter.

SSC JE Electrical 2019 with solution SET-2
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Observe the given table. The truth table represents gate?

In the exclusive OR gate (XOR gate) has two inputs

The ouput will be 1 when either input is 1 i.e X = 1 and Y = 1, but not when both the inputs are 1.

If both the input is zero i.e X = 0 and Y = 0, then the output is 0.