Question

Calculate the value of the angular acceleration of the motor using the given data: J= 50 kg-m^2, load torque = 40 N-m, motor torque = 10 N-m.

(a) -.7 rad/s^2

(b) -.6 rad/s^2

(c) -.3 rad/s^2

(d) -.4 rad/s^2

I have been asked this question during an internship interview.

This intriguing question comes from Dynamics topic in chapter Dynamics of Electrical Drives of Electric Drives

Answer 1

Correct option is (b) -.6 rad/s^2

The best explanation: Using the dynamic equation of motor J*(angular acceleration) = Motor torque – Load torque: 50*(angular acceleration) = 10-40 = -30, angular acceleration=-.6 rad/s^2. The motor will decelerate and will fail to start.