Gravitational constant G dimensions: MCQ with Answer and Explanation

Explanation:
Tension is towards centre, displacement is tangential (velocity). Force perpendicular to displacement, cos90°=0, work zero. Centripetal force does no work, doesn't change speed.

Explanation:
Lens maker: 1/f ∝ (n_rel - 1). In water, n_rel = n_glass/n_water ≈ 1.5/1.33 ≈ 1.13 < 1.5 (air). Smaller (n_rel-1) ⇒ larger f. Memory aid: 'Lens in denser medium: reduced power ⇒ longer focal length'. Optics application frequently tested in competitive exams.

Explanation:
R_t = R₀(1+α t) = 10(1+0.004×100) = 10(1.4) = 14 Ω.