A 2 kg object has potential energy 196 J at a height (g=9.8) of MCQ with Answer and Explanation

Explanation:
Latent heat of vaporization is the heat required to change unit mass from liquid to vapor at constant temperature (boiling point). For water, it's approximately 2260 kJ/kg. Latent heat of fusion applies to solid-liquid transition. Specific heat relates to temperature change without phase change. Thermal conductivity measures heat transfer rate through conduction. Memory aid: 'Vaporization = liquid to gas; fusion = solid to liquid'. This definition-based question tests precise terminology, crucial for thermodynamics sections in competitive exams where distractors often mix phase change terms.

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:
Specific heat capacity c is defined as heat required to raise temperature of unit mass (1 kg in SI) by 1°C (or 1 K). Formula: Q = mcΔT. Option D describes specific heat in cgs units (cal/g°C), but SI definition uses kg. Options A and C describe latent heats. Memory aid: 'Specific heat = per kg per degree'. This precise definition is crucial for calorimetry problems. Competitive exams often test unit awareness (kg vs g) to distinguish careful students. Always note the mass unit in the definition context.