PYQs Based test 9: Electrical Machines

The parameter of an equivalent circuit of a three-phase induction motor affected by reducing the rms value of the supply voltage at the rated frequency is

The direction of rotation of a single-phase capacitor run induction motor is reversed by

A three-phase cylindrical rotor synchronous generator has a synchronous reactance Xₛ and a negligible armature resistance. The magnitude of per phase terminal voltage is V${}_A$ and the magnitude of per phase induced emf is E${}_A$. Considering the following two statements, P and Q,

P: For any three-phase balanced leading load connected across the terminals of this synchronous generator, V${}_A$ is always more than E${}_A$

Q: For any three-phase balanced lagging load connected across the terminals of this synchronous generator, V${}_A$ is always less than E${}_A$

Which of the following options is correct?

A 3-phase, 4 pole, 400 V, 50 Hz, squirrel-cage induction motor is operating at a slip of 0.02. The speed of the rotor flux in mechanical rad/sec sensed by stationary observer, is closest to

A 200/400 V, 50 Hz, two – winding transformer is rated at 20 kVA. Its windings are connected as an auto-transformer of rating 200/600 V. A resistance load of 12 Ω is connected to the high voltage (600 V) side of the auto-transformer. The value of equivalent load resistance (in Ohm) as seen from low voltage side is_______