Q1:-The megger voltage for testing 250 v installation should be
1. 1000 v
2. 500 v
3. 300 v
4. 100 v
ANSWER:-2
Q2:-The direction of rotation of 3- phase revolving field can be changed by interchanging
1.
Rand Y phase only
2.
B and Y phase only
3.
R and B phase only
4.
Any two phase
ANSWER:-4
Q3:-The synchronous speed of the revolving field depends upon.
1. Number of poles
2.
Supply frequency
3.
Flux
4.
1 and 2
ANSWER:-4
Q4:-The rotor of a 3-phase induction motor rotates in the same direction as the direction of revolving field because of
1. Faraday’s laws of electro magnetic induction
2.
Lenz’s law
3.
Fleming’s right hand rule
4.
None of these
ANSWER:-2
Q5:-For induction motors normally
1. The rotor winding is connected to supply and the stator winding is short circuited
2.
The stator winding is connected to supply and
the rotor winding is short circuited
3.
Both the stator and the rotor windings are
connected to supply
4.
The stator winding is connected to supply and
the rotor winding is open circuited
ANSWER:-2
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