The escape velocity of a body from Earth is v_e. If Earth's radius shrinks to 1/4th keeping mass constant, escape velocity becomes MCQ with Answer and Explanation

Explanation:
Stethoscope amplifies sound.

Explanation:
Materials are classified by their magnetic properties. Ferromagnetic materials (Iron, Cobalt, Nickel) are strongly attracted to magnets. Paramagnetic materials (Aluminum, Platinum) are weakly attracted. Diamagnetic materials (Water, Bismuth, Copper, Gold) are actually weakly repelled by a magnetic field because they create an induced magnetic field in opposition to the externally applied one.

Explanation:
Q = mL = 3×336 = 1008 kJ. Direct latent heat formula application. Memory tip: 'Phase change: Q = mL; no temperature change'. Calorimetry calculation frequently tested in competitive exams.