The instrument used to measure pressure difference is MCQ with Answer and Explanation

Explanation:
Speed constant implies magnitude of velocity constant, so kinetic energy (½mv²) is constant. Velocity changes due to direction change. Acceleration (centripetal) is directed towards centre, changes direction. Linear momentum vector changes. So only kinetic energy remains constant.

Explanation:
n varies with λ ⇒ v = c/n varies ⇒ different refraction angles (Snell's law). Frequency constant; wavelength changes in medium. Memory aid: 'Dispersion: n(λ) ⇒ v(λ) ⇒ different bending; violet bends most'. Optics concept frequently tested in competitive exams.

Explanation:
Weight W = mg. On Earth: 10×10 = 100 N. On Moon: g_moon ≈ 10/6 ≈ 1.67 m/s². W_moon = 10×1.67 ≈ 16.7 N. Mass remains 10 kg; weight changes with gravity. Memory tip: 'Mass constant; weight ∝ g'. Tests mass-weight distinction and gravity variation, common conceptual question in competitive exams.