Doppler effect for sound depends on: MCQ with Answer and Explanation

Explanation:
In SHM, Total Energy (E) = 1/2 k A^2. Potential Energy (U) at displacement x is 1/2 k x^2. Kinetic Energy (K) is E - U = 1/2 k (A^2 - x^2). Given x = A/2. U = 1/2 k (A/2)^2 = 1/2 k (A^2 / 4) = E/4. Since total energy is conserved, K = E - E/4 = 3E/4. The ratio of Kinetic to Potential Energy (K:U) is (3E/4) / (E/4) = 3:1.

Explanation:
Bimetallic strip consists of two metals with different coefficients of linear expansion. On heating, one expands more, causing bending. Used in thermostats, fire alarms. Expansion difference causes curvature.

Explanation:
Joule's law states that heat produced H = I²Rt, where I is current, R resistance, t time. This quantifies electrical energy converted to thermal energy in resistors. Ohm's law relates V, I, R; Faraday's and Lenz's laws concern electromagnetic induction. Memory aid: 'Joule heating ∝ I²R'. This definition-based question tests knowledge of fundamental laws in electricity, commonly examined in competitive exams. Applications include electric heaters, fuses, and incandescent bulbs. Always distinguish Joule's law (heating) from power formulas (P=VI=I²R=V²/R).