The sound produced by a bat is MCQ with Answer and Explanation

Explanation:
Critical angle θ_c for total internal reflection: sinθ_c = n₂/n₁, where n₁ > n₂. Here n₁=1.5 (glass), n₂=1 (air), so sinθ_c = 1/1.5 = 2/3 ≈ 0.6667 ⇒ θ_c = sin⁻¹(0.6667) ≈ 41.8° ≈ 42°. Memory aid: 'sinθ_c = 1/n for glass to air'. This calculation tests understanding of total internal reflection conditions, crucial for optics in competitive exams. Always ensure light travels from denser to rarer medium for TIR to be possible; otherwise, no critical angle exists.

Explanation:
Raman effect discovered in 1928, Nobel in 1930.

Explanation:
Impulse = F Δt = Δp (change in momentum). Derived from Newton's second law. Force is rate of change of momentum. Impulse-momentum theorem important for collisions.