A body of volume 100 cc weighs 80 g in air. It will float in water with MCQ with Answer and Explanation

Explanation:
Dispersion is splitting of light into constituent colours due to variation of refractive index with wavelength. Violet deviates most, red least. Prism doesn't absorb but disperses. Rainbow formation is due to dispersion, refraction, reflection in water droplets.

Explanation:
Phase difference 90°, power factor zero, average power zero.

Explanation:
Convex mirror diverges rays, gives erect, diminished, virtual image with wider field. Concave would magnify but narrow field. Plane gives normal view. Safety advantage.