The principle of a lightning conductor is MCQ with Answer and Explanation

Explanation:
Electrical energy (E) = Power (P) × Time (t). Power = 60 W = 0.06 kW. Time per day = 5 hours. Total time in 30 days = 5 × 30 = 150 hours. Energy = 0.06 kW × 150 h = 9 kWh (or 9 units of electricity). One kWh is the commercial unit of energy.

Explanation:
Leading zeros (before first non-zero digit) are not significant. So 0.0034060: the first non-zero is 3, then 4,0,6 are significant, and the trailing zero after decimal is significant. Thus significant digits are 3,4,0,6,0 — 5 digits. Note: The last zero indicates precision. Answer is 5.

Explanation:
When a wave (like light or sound) changes mediums, its velocity changes due to the new medium's optical or mechanical density. Wavelength changes proportionally with velocity (v = fλ). However, frequency is determined solely by the source generating the wave and the energy of the photons/particles, and it remains absolutely constant.