Which of the following electromagnetic waves has the highest frequency? MCQ with Answer and Explanation

Explanation:
F = (9/5)C + 32. Given F = 2C: 2C = 1.8C + 32 ⇒ 0.2C = 32 ⇒ C = 160°. Verify: F = 2×160 = 320°; formula: (9/5)×160+32 = 288+32 = 320°. Memory aid: Solve linear equation for temperature conversion problems. Algebraic manipulation of scale relations frequently tested in competitive exams.

Explanation:
Apparent loss in weight = buoyant force = weight in air - weight in water = 5 N. Archimedes principle. Apparent weight = 20-5 = 15 N.

Explanation:
R' = ρ(3L)/(2A) = (3/2)(ρL/A) = 1.5R. Resistance scales directly with length, inversely with area. Memory aid: 'R ∝ L/A; changes multiply'. Proportional reasoning problem testing resistance formula, frequently appearing in competitive electricity sections.