Which characteristic of a sound wave determines its pitch? MCQ with Answer and Explanation

Explanation:
r_cm = (m1 r1 + m2 r2)/(m1+m2). Closer to heavier mass.

Explanation:
When you pull a roller at an upward angle, the vertical component of the applied force acts strictly upwards, reducing the normal reaction (N = mg - Fsin_theta) and thus reducing friction (muN). When you push it at a downward angle, the vertical component adds to the weight (N = mg + Fsin_theta), increasing the normal reaction and consequently increasing the rolling friction.

Explanation:
Total internal reflection (TIR) is exploited in optical fibers for light transmission with minimal loss (core-cladding interface). In diamonds, high refractive index (n≈2.4) gives small critical angle (~24°), so most light undergoes TIR, enhancing brilliance through multiple reflections. Memory aid: 'TIR applications: optical fibers (communication), diamonds (sparkle), prisms (binoculars)'. This application question tests optics uses, frequently appearing in competitive exams. Always link physical principles to technological applications; competitive exams emphasize practical relevance of theoretical concepts.