A body is thrown vertically upward. At the highest point, its acceleration is MCQ with Answer and Explanation

Explanation:
A concave mirror forms real and inverted images in most positions. The only exception is when the object is placed very close to the mirror, specifically between the pole (P) and the principal focus (F). In this position, the reflected rays diverge, forming a virtual, erect, and magnified image behind the mirror. This is why concave mirrors are used as shaving or makeup mirrors.

Explanation:
Interference (constructive/destructive superposition) is wave phenomenon. Young's double-slit confirmed light's wave nature. Particle nature shown by photoelectric effect. Memory aid: 'Interference/diffraction ⇒ wave; photoelectric ⇒ particle'. Wave-particle duality frequently tested in competitive exams.

Explanation:
(1/2)ⁿ = 1/32 ⇒ 2ⁿ = 32 ⇒ n = 5 half-lives. Exponential decay calculation. Memory aid: '1/2ⁿ remaining; 1/32 = 1/2⁵ ⇒ 5 half-lives'. Radioactivity arithmetic frequently tested in competitive exams.