Question

Calculate the moment of inertia of the rod about its end having a mass of 39 kg and length of 88 cm.

(a) 9.91 kgm^2

(b) 9.92 kgm^2

(c) 9.96 kgm^2

(d) 9.97 kgm^2

The question was posed to me in an online interview.

The above asked question is from DC Motors topic in portion Characteristics of DC & AC Motors of Electric Drives

Answer 1

Correct option is (c) 9.96 kgm^2

The explanation: The moment of inertia of the rod about its end can be calculated using the formula I=ML^2÷3. The mass of the rod about its end and length is given. I=(39)×.33×(.88)^2=9.96 kgm^2. It depends upon the orientation of the rotational axis.