The weight of a body is maximum at MCQ with Answer and Explanation

Explanation:
Average speed = total distance / total time = d / ( (d/2)/v1 + (d/2)/v2 ) = 2v1v2/(v1+v2).

Explanation:
R ∝ L² (volume constant). L'=3L => R' = 3² × 6 = 9×6 = 54 Ω. Generally, R' = n² R for stretching n times. Important concept.

Explanation:
Gamma rays have wavelengths < 10⁻¹² m, shortest in EM spectrum. X-rays 10⁻¹⁰-10⁻⁸ m. UV 10⁻⁸-4×10⁻⁷ m. IR longer. So gamma rays shortest. Highest frequency, energy.