Work done against gravity in lifting a 5 kg mass through 2 m (g=10) is MCQ with Answer and Explanation

Explanation:
Dispersion: red has longest wavelength, lowest refractive index, deviates least. Violet deviates most. So spectrum: red at top (least deviation), violet at bottom.

Explanation:
The power (P) of a lens indicates its converging or diverging ability. It is mathematically defined as the reciprocal of the focal length (f), provided the focal length is measured in meters. The formula is P = 1 / f(in meters). The SI unit of power for a lens is the Diopter (D). A focal length of 0.5m gives a power of 2D.

Explanation:
Volume V = (4/3)πr³. Fractional error ΔV/V = 3 Δr/r. Percentage error = 3 × 2% = 6%. Important for error analysis in competitive exams.