If a ring-shaped iron plate has inner diameter \(d_1\) and outer diameter \(d_2\), then the area of the plate will be:

Q.If a ring-shaped iron plate has inner diameter \(d_1\) and outer diameter \(d_2\), then the area of the plate will be: (a) \(\pi(d_1^2-d_2^2)\) (b) \(\cfrac{\pi}{4}(d_2^2-d_1^2)\) (c) \(\cfrac{\pi}{4}(d_1^2-d_2^2)\) (d) \(\cfrac{1}{4}(d_2^2-d_1^2)\)

Answer: B

The area of the ring-shaped plate will be: \[ = \pi \left(\frac{d_2}{2}\right)^2 - \pi \left(\frac{d_1}{2}\right)^2 = \pi \cdot \frac{d_2^2}{4} - \pi \cdot \frac{d_1^2}{4} = \frac{\pi}{4}(d_2^2 - d_1^2) \]