Question

Calculate the value of the angular acceleration of the machine using the given data: J = .541 kg-m^2, load torque = 10 N-m, motor torque = 2 N-m.

(a) 45 rad/s^2

(b) The machine will fail to start

(c) 30 rad/s^2

(d) 51 rad/s^2

I have been asked this question in exam.

My doubt stems from Motors Rating and Heating topic in section Rating and Heating of Motors of Electric Drives

Answer 1

Correct choice is (b) The machine will fail to start

Explanation: Using the dynamic equation of motor J×(angular acceleration) = Motor torque – Load torque: .541×(angular acceleration) = 2-10=-8, angular acceleration=-14.78 rad/s^2. The load torque is greater than the motor torque. The motor will fail to start.