GATE EE 2012 Question Paper (12-Feb-2012) (Shift 2)

The locked rotor in a 3 phase star connected 15 kW 4 pole 230 V 50 Hz IM runs at rated conditions of 50A. Neglecting losses and magnetising current the approximate locked rotor line current drawn when the motor is connected to 236 V 57 Hz is

A single phase 10KVA 50Hz transformer 1 KV primary winding with current 0.5A and 55W at the rated voltage and frequency, on no load. A second transformer has a core with all its linear dimensions √2 times the corresponding dimensions of the first transformer. The core thickness and laminations are the same in both the transformers. The primary winding of both the transformers have same number of turns. If the rated voltage of 2KV at 50Hz is applied to the primary of the second transformer, the no load current and power are:

In the 3-phase inverter circuit shown, the load is balanced and the gating scheme is 180°-conduction mode. All the switching devices are ideal. (V${}_d$ = 300 V)

In the 3-phase inverter circuit shown, the load is balanced and the gating scheme is 180°-conduction mode. All the switching devices are ideal. (V${}_d$ = 300 V)

With 10 V dc connected at port A in the linear nonreciprocal two-port network shown below, the following were observed:

i) 1 Ω connected at port B draws a current of 3 A

ii) 2.5 Ω connected at port B draws a current of 2 A