The atmosphere exerts pressure because MCQ with Answer and Explanation

Explanation:
When a body is lifted against gravity, work done (mgh) is stored as gravitational potential energy. This energy can be recovered when the body falls. Kinetic energy relates to motion, thermal to heat, elastic to deformed materials. The conservation of energy principle states that work done against conservative forces becomes potential energy. Formula: PE = mgh, where h is height above reference. Memory aid: 'Potential' means stored energy due to position. This conceptual question tests energy transformation understanding, frequently appearing in work-energy theorem applications in competitive exams.

Explanation:
Newton's third law states that to every action, there is an equal and opposite reaction. Crucially, action and reaction forces always act on two different bodies. Because they act on different bodies, they do not cancel each other out, and each body experiences a net force based on the reaction it receives.

Explanation:
Rainbow: sunlight enters raindrop (refraction + dispersion), reflects internally (TIR), exits with further refraction. Primary rainbow: one TIR; secondary: two TIRs. Memory tip: 'Rainbow = refraction + dispersion + TIR in water droplets'. Application question testing atmospheric optics, frequently appearing in competitive exams.