Question

Calculate the value of the angular acceleration of the motor using the given data: J = .01 kg-m^2, load torque= 790 N-m, motor torque= 169 N-m.

(a) -62100 rad/s^2

(b) -62456 rad/s^2

(c) -34056 rad/s^2

(d) -44780 rad/s^2

The question was asked in an interview for internship.

This is a very interesting question from Starting topic in section Starting of Electric Drives

Answer 1

Right choice is (a) -62100 rad/s^2

The explanation is: Using the dynamic equation of motor J*(angular acceleration) = Motor torque – Load torque: .01*(angular acceleration) = 169-790=-621, angular acceleration=-62100 rad/s^2.The motor will decelerate and will fail to start.