Q.1
The starting torque of a squirrel-cage induction motor is
Q.2
Which of the following is not the standard voltage for power supply in India?
Q.3
When the equivalent circuit diagram of doouble squirrelcage induction motor is constructed the two cages can be considered
Q.4
The use of higher flux density in the transformer design
Q.5
A transformer has a 1:6 turns ratio and a secondary coil load resistance of 470 Ω. The load resistance as seen by the source is
Q.6
While conducting short-circuit test on a transformer the following side is short circuited
Q.7
Spacers are provided between adjacent coils
Q.8
A shell-type transformer has
Q.9
The magnetising current of a transformer is usually small because it has
Q.10
Which of the following insulating materials can withstand the highest temperature safely?
Q.11
An ideal transformer has infinite values of primary and secondary inductances. The statement is
Q.12
During open circuit test of a transformer
Q.13
Which of the following is not a routine test on transformers?
Q.14
In a transformer the tappings are generally provided on
Q.15
No-load current in a transformer
Q.16
During short circuit test iron losses are negligible because
Q.17
If a transformer is continuously operated the maximum temperature rise will occur in
Q.18
In Ns is the synchronous speed and s the slip, then actual running speed of an induction motor will be
Q.19
Distribution transformers are generally designed for maximum efficiency around
Q.20
In case of 3-phase induction motors, plugging means
Q.21
The main reason for generation of harmonics in a transformer could be
Q.22
The purpose of providing iron core in a step-up transformer is
Q.23
If R₂ is the resistance of secondary winding of the transformer and K is the transformation ratio then the equivalent secondary resistance referred to primary will be
Q.24
Two transformers operating in parallel will share the load depending upon their
Q.25
The primary coil of a transformer is connected to a 60 V ac source. The secondary coil is connected to a 330 Ω load. The turns ratio is 3:1. What is the secondary voltage?
Q.26
Greater the secondary leakage flux
Q.27
A transformer core is laminated to
Q.28
Hysteresis loss in a transformer varies as (Bmax = maximum flux density)
Q.29
The no load current in a transformer lags behind the applied voltage by an angle of about
Q.30
Power transformers are generally designed to have maximum efficiency around
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