SSC JE Electrical Engineering 2013 Paper

Question : 121 of 200

Marks: +1, -0

To maximize the driving torque in an induction type instrument, flux produced by shunt coil and series coil should be

in phase with each other
in quadrature with each other
displaced by 45° with respect to each other
out of phase with respect to each other

Solution:

The deflecting torque of induction type instrument is

T_d =ϕ_1ϕ_2\sinβ\cosα

The torque in induction type instrument is directly proportional to 'cos α'. Therefore in order to maximize the torque, the angle should be near to zero.
The torque in induction type instrument is directly proportional to 'sin β'. Therefore the angle 'β' should be near to 90° in order to maximize the torque. The angle 'β' is the angle between two shunt coil flux and series coil flux and quadrature means 90°.

Go to Question:

Prev Question

Next Question