The scientist who formulated the universal law of gravitation is: MCQ with Answer and Explanation

Explanation:
Convex mirror and concave lens always produce virtual images. Concave mirror and convex lens can produce real images under certain conditions. So convex mirror always virtual.

Explanation:
Range R = u²sin(2θ)/g. sin(2θ) maximum (=1) when 2θ=90° ⇒ θ=45°. Standard result for level ground projection. Memory aid: 'Max range at 45°; max height at 90°'. Projectile motion fact frequently tested in competitive exams.

Explanation:
Newton is a derived unit representing force, defined as kg·m/s². Kelvin (temperature), Ampere (current), and Mole (amount of substance) are fundamental SI units. Derived units are combinations of fundamental units through physical relationships. Newton comes from Newton's second law: F = ma. Memory aid: Remember the seven fundamental SI units: meter, kilogram, second, ampere, kelvin, mole, candela. All others like newton, joule, watt are derived. This distinction is essential for unit conversion questions in competitive exams.