Which of the following regions of a transistors are, respectively, heavily dopped and lightly dopped?

A hole is drilled half way to the centre of the earth. A body weighs 300 N on the surface of the earth. How much will, it weigh at the bottom of the hole?

Eight identical drops of water falling through air with uniform velocity of $10 \mathrm{~cm} / \mathrm{s}$ combine to form a single drop of big size, then terminal velocity of the big drop will be

A solid sphere rolls down from top of inclined plane, 7 m high, without slipping. Its linear speed at the foot of plane is $\left(g=10 \mathrm{~m} / \mathrm{s}^2\right)$