The color of sky is blue due to MCQ with Answer and Explanation

Explanation:
Silver excellent conductor. Air is insulator.

Explanation:
Force (weight) is vertical (upward to support), displacement horizontal, angle 90°, cos90°=0, work = 0. No work against gravity because vertical height doesn't change. Energy spent is internal muscular effort, but physics work zero.

Explanation:
Laws of reflection: (1) Angle of incidence (i) equals angle of reflection (r); (2) Incident ray, reflected ray, and normal at point of incidence all lie in the same plane. Option D describes refraction, not reflection. These laws hold for all reflecting surfaces (plane, curved). Memory tip: 'i = r and coplanar rays'. This definition-based question tests precise recall of fundamental optics laws, frequently examined in competitive exams. Always distinguish reflection laws (i=r) from refraction laws (Snell's law: n₁sin i = n₂sin r).