SSC JE 2017: Electrical Machines Rankers Quiz 1

Attempt now to get your rank among 1453 students!

Question 1

An over-excited synchronous motor behaves as ……………….

• Aa resistor
• Ban inductor
• Ca capacitor
• Dnone of the above

Question 2

The power-factor correction capability of a loaded synchronous motor ________with the increase in mechanical load.

• Adecreases
• Bincreases
• Cremains unchanged
• Dnone of the above

Question 3

The pull-out torque of a 3-phase synchronous motor varies as

• Aapplied voltage V
• BV²
• C1/V
• D

Question 4

When a number of alternators are operating in parallel, the power factor at which each operates is determined by ……………………

• Apower factor of the load
• Bdriving torque of the prime mover
• Cits field excitation
• Dnone of the above

Question 5

At starting, the windings of a 230 V, 50 Hz, split-phase induction motor have the following parameters:

Main winding is at an angle of 28 degrees and Starting winding is at an angle of -62 degrees from +x direction.



What will be the power factor of the motor ?

• A0.5 lag
• B0.7 lag
• C0.85 lag
• D0.24 lag

Question 6

For speeds higher than say 3000 r. p. m. , the single phase motor used is

• Asingle phase induction motor
• Bsingle phase synchronous motor
• Cuniversal motor
• Dnone of the above

Question 7

A resistive load is to be impedance matched by a transformer to a source with of internal resistance. The ratio of primary to secondary turns of transformer should be

• A10
• B15
• C20
• D25

Question 8

A source of internal impedance is connected to a load through a transformer of turns ratio 2 : 1. For maximum power transfer, the load impedance should be

• A
• B
• C
• Dnone of the above

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