Question

Calculate the moment of inertia of the thin spherical shell having a mass of 3 kg and diameter of 6 cm.

(a) .0178 kgm^2

(b) .0147 kgm^2

(c) .0398 kgm^2

(d) .0144 kgm^2

I had been asked this question in examination.

I'd like to ask this question from Effect of Starting on Power Supply, Motor and Load topic in section Starting of Electric Drives

Answer 1

Correct choice is (a) .0178 kgm^2

The best I can explain: The moment of inertia of the thin spherical shell can be calculated using the formula I=mr^2×.66. The mass of the thin spherical shell and diameter is given. I=(3)×.66×(.03)^2=.0178 kgm^2. It depends upon the orientation of the rotational axis.