WBJEE 2024 Physics & Chemistry Paper

After we will apply the concept of energy conservation, as the surface of the bowl is smooth, small sphere does not roll as there is no friction.
So, small sphere does not gain rotational kinetic energy.
Hence, by energy conservation,
‌∆KE‌ Loss in PE ‌
‌KEf−0=mgR−mg(r)
‌⇒KEf=mg(R−r)
Hence, total kinetic energy of the spheres at the lowest point A is
KE=mg(R−r)