The specific heat capacity of a substance is defined as the amount of heat required to:
A. Melt 1 kg of the substance at its melting point
B. Raise the temperature of 1 g of the substance by 1°C
C. Vaporize 1 kg of the substance at its boiling point
D. Raise the temperature of 1 kg of the substance by 1°C
Answer: Option D
Solution (By JKSSB Mock Tests)
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.
Explanation:
In free fall under gravity alone, mechanical energy (kinetic + potential) is conserved, assuming no air resistance. Potential energy decreases while kinetic energy increases, sum constant. Law of conservation of mechanical energy. Non-conservative forces absent.
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