The voltage applied to a transformer primary is increased keeping V/f constant. With this, the core loss ____ and the magnetizing current (Im) ____

For trasnformer:
1. e = 4.44fφ*Turns
2. V/f ≈ e/f ∝ φ ∝ B
3. Eddy Current loss, Pe ∝ B²f² ∝ f² (as B is constant if V/f is constant)
4. Hysteresis loss, Ph ∝ B^1.6*f ∝ f
If V/f is constant, B is constant, mmf required to create B is constant, Im is constant.

A three-phase, 4-pole, 50 Hz induction motor runs at 1425 rpm. Find out the percentage slip of the induction motor.

Slip, s = (Ns - Nr)/Ns
Ns = 120f/P
Ns = 1500 rpm

s = (1500 - 1425)/1500
s = 0.05
%s = 5%

Which of the following is a national organisation monitoring the doping control programme in sports in India?

Vikram Seth is associated with which of the following fields?

A sudden, non power frequency change in the steady state condition of voltage or current that is bidirectional in polarity is called as

Oscillatory transient is the a sudden, non power frequency change in the steady state condition of voltage or current that is bidirectional in polarity.

In transformer, a Sweep Frequency Response Analysis (SFRA) test will help detect ____

Frequency response analysis is the technique whereby a sinusoidal test signal is used to measure points on the frequency response of a transfer function or impedance function.
Sweep Frequency Response Analysis (SFRA) testing provides insight into the mechanical and electrical integrity of transformers.

Main Purpose of SFRA Test:
Transformer Core displacement
Winding displacement for both rotor and transformer
Broken or loosen clamp connections
Inter turn short circuit
Internal short circuit
Winding to Core Earth fault
Winding Open circuit condition