The frequency of a wave is 1 kHz. Its time period is MCQ with Answer and Explanation

Explanation:
Force = rate of change of momentum: F = Δp/Δt. Thus Δp = F × Δt = 10 N × 5 s = 50 kg·m/s. Since initial momentum was zero (body at rest), final momentum = 50 kg·m/s. Alternatively, acceleration a = F/m = 10/2 = 5 m/s², velocity after 5s: v = u + at = 0 + 5×5 = 25 m/s, momentum p = mv = 2×25 = 50 kg·m/s. Both methods confirm. Memory tip: Impulse (FΔt) equals change in momentum. This direct application of Newton's second law is essential for dynamics problems in competitive exams.

Explanation:
Ice displaces water equal to its weight; when melted, occupies exactly that volume. Level unchanged.

Explanation:
Polarization requires transverse waves (oscillations perpendicular to propagation). Light, radio waves, X-rays are electromagnetic transverse waves and can be polarized. Sound waves in air are longitudinal (oscillations parallel to propagation) and cannot be polarized. Memory tip: 'Polarization ⇒ transverse waves only; sound is longitudinal ⇒ no polarization'. This wave property question tests understanding of wave types, frequently examined in competitive exams. Always classify waves as transverse/longitudinal to determine polarization possibility; this is a common conceptual trap.