Exams › GATE › Technical

A 400 V, 50 Hz, 30 hp, three-phase induction motor is drawing 50 A current at 0.8 power factor lagging. The stator and rotor copper losses are 1.5 kW and 900 W respectively. The friction and windage losses are 1050 W and the core losses are 1200 W. The air-gap power of the motor will be

1. (A) 23.06 kW
2. (B) 24.11 kW
3. (C) 25.01 kW
4. (D) 26.21 kW

Correct answer: (C) 25.01 kW

Solution

The air-gap power is calculated by subtracting all losses from the input power. The input power can be determined from the current, voltage, and power factor, and after accounting for stator and rotor copper losses, friction and windage losses, and core losses, the remaining power is the air-gap power, which in this case is 25.01 kW.

Related GATE Technical questions

• The equivalent circuits of a diode, during forward biased and reverse biased conditions, are shown in the figure. If such a diode is used in clipper circuit of figure given above, the output voltage (vₒ) of the circuit will be
• An input device is interfaced with Intel 8085A microprocessor as memory mapped I/O. The address of the device is 2500H. In order to input data from the device to accumulator, the sequence of instructions will be
• Distributed winding and short chording employed in AC machines will result in
• In a stepper motor, the detent torque means
• A two machine power system is shown below. Transmission line XY has positive sequence impedance of Z1 Ω and zero sequence impedance of Z0 Ω. An ‘a’ phase to ground fault with zero fault impedance occurs at the centre of the transmission line. Bus voltage at X and line current from X to F for the phase ‘a’, are given by Va Volts and Ia Amperes, respectively. Then, the impedance measured by the ground distance relay located at the terminal X of line XY will be given by
• The impulse response of a causal linear time-invariant system is given as h(t). Now consider the following two statements: Statement (I): Principle of superposition holds Statement (II): h(t) = 0 for t < 0 Which one of the following statements is correct?

⚔️ Practice GATE Technical free + battle 1v1 →