The part of the electromagnetic spectrum used in remote controls is MCQ with Answer and Explanation

Explanation:
Interference (constructive/destructive superposition) is wave phenomenon. Young's double-slit confirmed light's wave nature. Particle nature shown by photoelectric effect. Memory aid: 'Interference/diffraction ⇒ wave; photoelectric ⇒ particle'. Wave-particle duality frequently tested in competitive exams.

Explanation:
Position-time graph as parabola: x = x₀ + ut + ½at². This quadratic form indicates constant acceleration 'a'. If acceleration were changing, the graph would be cubic or higher order. Constant velocity would produce a straight line (linear graph). Upward opening parabola implies positive acceleration. Graph interpretation skill is essential: slope of x-t graph = velocity; curvature indicates acceleration. Memory tip: Parabolic x-t graph ⇔ constant acceleration; linear x-t graph ⇔ constant velocity. Competitive exams frequently test graph-concept correlations.

Explanation:
Naphthalene (mothballs), camphor, dry ice sublime (solid → gas). Ice melts. Iron solid till melting. Water evaporates from liquid. Sublimation skips liquid phase.