Heat — Class 7 Science NCERT Solutions (Free)

Free step-by-step NCERT solutions for Class 7 Science chapter "Heat" — 8 important questions with detailed answers for CBSE board exam preparation.

TL;DR: Free step-by-step NCERT solutions for Class 7 Science chapter "Heat" — 8 important questions with detailed answers for CBSE board exam preparation.

By Syllab.in · Updated Jun 14, 2026

Key Questions Covered:

Define heat.
What is the difference between heat and temperature?
A body is heated from 20°C to 50°C. Calculate the rise in temperature.
If 100 g of water is heated from 25°C to 75°C, calculate the heat energy requ…
What is thermal expansion?
Define specific heat capacity.
+ 2 more questions in the full chapter

Solutions Summary:

Question	Status
Define heat.	✓ Solved
What is the difference between heat and temperature?	✓ Solved
A body is heated from 20°C to 50°C. Calculate the rise in…	✓ Solved
If 100 g of water is heated from 25°C to 75°C, calculate …	✓ Solved
What is thermal expansion?	✓ Solved
Define specific heat capacity.	✓ Solved

Showing 6 of 8 questions

Q1: Define heat.

Heat is a form of energy that flows from a hotter body to a colder body. It is measured in joules (J) or calories (cal). 1 calorie = 4.2 joules approximately.

Q2: What is the difference between heat and temperature?

Temperature is the measure of the degree of hotness of a body. Heat is the energy transferred from one body to another due to temperature difference. Temperature is measured in °C, °F or K; heat is measured in joules or calories.

Q3: A body is heated from 20°C to 50°C. Calculate the rise in temperature.

Rise in temperature = Final temperature - Initial temperature = 50°C - 20°C = 30°C The rise in temperature is 30°C.

Q4: If 100 g of water is heated from 25°C to 75°C, calculate the heat energy required. (Specific heat capacity of water = 4200 J/kg°C)

Given: m = 100 g = 0.1 kg, T₁ = 25°C, T₂ = 75°C, c = 4200 J/kg°C ΔT = 75 - 25 = 50°C Q = m × c × ΔT Q = 0.1 × 4200 × 50 Q = 21,000 J or 21 kJ

Q5: What is thermal expansion?

Thermal expansion is the increase in size of a substance when heated. Most substances expand when heated and contract when cooled. Different substances expand at different rates.

Q6: Define specific heat capacity.

Specific heat capacity is the amount of heat energy required to raise the temperature of 1 kg of a substance by 1°C. Unit: J/kg°C Different substances have different specific heat capacities.

Showing 6 of 8 questions. Visit the full page for complete solutions.