GATE EE 2025 | GATE EE Year Wise Previous Years Questions

GATE EE 2025

Numerical

-0

The induced emf in a 3.3 kV , 4-pole, 3-phase, star-connected synchronous motor is considered to be equal and in phase with the terminal voltage under no load condition. On application of a mechanical load, the induced emf phasor is deflected by an angle of $2^{\circ}$ mechanical with respect to the terminal voltage phasor. If the synchronous reactance is $2 \Omega$, and stator resistance is negligible, then the motor armature current magnitude, in ampere, during loaded condition, is closest to __________ . (round off to two decimal places)

Your input ____

GATE EE 2025

MCQ (Single Correct Answer)

-0.67

A DC series motor with negligible series resistance is running at a certain speed driving a load, where the load torque varies as cube of the speed. The motor is fed from a 400 V DC source and draws 40 A armature current. Assume linear magnetic circuit. The external resistance, in $\Omega$, that must be connected in series with the armature to reduce the speed of the motor by half, is closest to

23.28

4.82

46.7

GATE EE 2025

MCQ (Single Correct Answer)

-0.67

A 3-phase, $400 \mathrm{~V}, 4$ pole, 50 Hz star connected induction motor has the following parameters referred to the stator :

$$ R_r^{\prime}=1 \Omega, X_S=X_r^{\prime}=2 \Omega $$

Stator resistance, magnetizing reactance and core loss of the motor are neglected. The motor is run with constant V/f control from a drive. For maximum starting torque, the voltage and frequency output, respectively, from the drive, is closest to,

400 V and 50 Hz

200 V and 25 Hz

100 V and 12.5 Hz

300 V and 37.5 Hz

GATE EE 2025

MCQ (Single Correct Answer)

-0.33

Which one of the following figures represents the radial electric field distribution $E_R$ caused by a spherical cloud of electrons with a volume charge density. $\rho=-3 \rho_0$ for $0 \leq R \leq a$ (both $\rho_0, a$ are positive and $R$ is the radial distance) and $\rho=0$ for $R>a$ ?

Fig. (i)