Which of the following is an ohmic conductor? MCQ with Answer and Explanation

Explanation:
Acceleration due to gravity at height h: g' = gR²/(R+h)², where R is Earth's radius. Given h = R, so g' = gR²/(2R)² = gR²/4R² = g/4. This inverse square law dependence arises from Newton's law of gravitation. At depth, variation differs, but for height, this formula applies. Memory aid: Double the distance from center ⇒ gravity becomes one-fourth. This standard result is frequently tested in gravitation sections of competitive exams. Always verify whether height or depth is specified, as formulas differ significantly.

Explanation:
Outside N to S, inside S to N, forming closed loops.

Explanation:
Isaac Newton formulated three laws of motion and law of universal gravitation in Principia (1687). He also contributed to calculus, optics. Galileo experiments on motion. Einstein relativity.