Question

Calculate the moment of inertia of the apple having a mass of .4 kg and diameter of 12 cm.

(a) .0008 kgm^2

(b) .0007 kgm^2

(c) .0009 kgm^2

(d) .0001 kgm^2

I have been asked this question at a job interview.

The doubt is from Energy Relations During Starting in portion Starting of Electric Drives

Answer 1

The correct option is (b) .0007 kgm^2

For explanation I would say: The moment of inertia of the apple can be calculated using the formula I=mr^2×.5. The mass of the apple and diameter is given. I=(.4)×.5×(.06)^2 = .0007 kgm^2. It depends upon the orientation of the rotational axis.