Which of the following is an example of a non-contact force? MCQ with Answer and Explanation

Explanation:
Nuclear fission is the splitting of a heavy nucleus (e.g., uranium-235, plutonium-239) into lighter nuclei, releasing energy and neutrons. This process powers nuclear reactors and atomic bombs. Fusion combines light nuclei (e.g., hydrogen to helium), powering stars. Memory aid: 'Fission = splitting heavy; Fusion = joining light'. This conceptual question tests understanding of nuclear reactions, frequently examined in competitive exams. Always link fission to chain reactions (neutrons induce further fissions) and critical mass concepts.

Explanation:
Constant speed does not imply zero acceleration if direction changes, e.g., uniform circular motion has centripetal acceleration. Velocity may change direction. Displacement magnitude ≤ distance. So only option B is correct.

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.