Heat MCQs (241–270) with Answers and Explanations help students practice important objective questions from the Heat chapter for quick revision.
This set focuses on temperature scales, calorimetry formulas, thermal expansion applications, and common heat transfer concepts.
241. The SI unit of temperature difference is:
Correct Answer: B
Kelvin (K) is used for SI temperature and temperature difference.
242. The heat required to change 1 kg of ice at 0°C to water at 0°C is:
Correct Answer: C
Melting of ice needs latent heat of fusion without temperature change.
243. The heat required to change 1 kg of water at 100°C into steam at 100°C is:
Correct Answer: A
Boiling needs latent heat of vaporization at constant temperature.
244. The calorimetry equation is:
Correct Answer: D
Heat gained or lost is given by Q = m × c × ΔT.
245. The unit of specific heat capacity is:
Correct Answer: B
Specific heat capacity is measured in J/kgK (or J/kg°C).
246. Which one is a good insulator of heat?
Correct Answer: C
Air is a poor conductor, so it works as an insulator.
247. The best conductor of heat among common metals is:
Correct Answer: D
Silver has the highest thermal conductivity among common metals.
248. The handle of a cooking utensil is made of wood/plastic because:
Correct Answer: A
Insulators reduce heat transfer, so handles remain cooler.
249. Cooking utensils are often made of copper/aluminium because:
Correct Answer: B
Good conductors help in quick and uniform heating.
250. The transfer of heat in a metal spoon kept in hot tea is by:
Correct Answer: A
Heat travels through the spoon by conduction.
251. The mode of heat transfer responsible for heating water in a kettle is mainly:
Correct Answer: B
Convection currents transfer heat throughout the water.
252. The mode of heat transfer in vacuum is:
Correct Answer: C
Radiation does not require a medium to transfer heat.
253. The heat from the Sun reaches Earth by:
Correct Answer: D
Solar heat travels through vacuum by radiation.
254. Black clothes are preferred in winter because:
Correct Answer: A
Black surfaces absorb maximum radiation and keep the body warm.
255. White clothes are preferred in summer because:
Correct Answer: B
White surfaces reflect heat radiation and keep the body cooler.
256. Which surface is the best emitter of heat?
Correct Answer: D
Dull black surfaces emit heat radiation strongly.
257. The coefficient of linear expansion has unit:
Correct Answer: C
Expansion coefficients are measured per degree temperature change.
258. The expansion of solids is generally:
Correct Answer: A
Solids expand the least compared to liquids and gases.
259. A thermos flask prevents heat loss mainly by:
Correct Answer: B
Vacuum stops conduction/convection and silvering reduces radiation.
260. The process of changing gas into liquid is called:
Correct Answer: D
Condensation is the change of state from gas to liquid.
261. The process in which solid changes directly into gas is:
Correct Answer: B
Sublimation is direct change from solid to gas (e.g., camphor).
262. The temperature at which a liquid changes into gas is called:
Correct Answer: C
Boiling point is the temperature at which a liquid boils into gas.
263. Heat transfer through liquids takes place mainly by:
Correct Answer: B
Convection currents transfer heat in liquids and gases.
264. The factor that increases the rate of evaporation is:
Correct Answer: D
Wind speed removes vapour quickly and increases evaporation.
265. Water is used as a coolant in car radiators because:
Correct Answer: A
Water absorbs large heat without large temperature rise.
266. The temperature of boiling water remains constant because:
Correct Answer: C
Heat is used for change of state (latent heat), not temperature rise.
267. The temperature of melting ice remains constant because:
Correct Answer: B
Heat is used to change state from solid to liquid.
268. Water has maximum density at:
Correct Answer: A
Water shows maximum density at 4°C (anomalous behaviour).
269. The phenomenon of water expanding below 4°C is called:
Correct Answer: D
Water expands on cooling from 4°C to 0°C (anomalous expansion).
270. Heat always flows from:
Correct Answer: B
Heat transfers naturally from higher temperature to lower temperature.
Heat MCQs (241–270) FAQs
1. What topics are covered in Heat MCQs (241–270)?
This set includes calorimetry basics, latent heat, heat transfer, and temperature-related concepts.
2. Are these Heat MCQs helpful for competitive exams?
Yes, they improve objective problem-solving skills and concept clarity in Heat chapter questions.
3. Do these questions have answers and explanations?
Yes, every question includes the correct answer with a short explanation for revision.
4. How do these Heat MCQs help students?
They improve speed, accuracy, and strengthen important concepts like conduction, convection, and radiation.
5. What is the best way to practice this Heat MCQ set?
Solve all MCQs, review explanations, and repeat practice of weak areas for best results.
This set includes calorimetry basics, latent heat, heat transfer, and temperature-related concepts.
2. Are these Heat MCQs helpful for competitive exams?
Yes, they improve objective problem-solving skills and concept clarity in Heat chapter questions.
3. Do these questions have answers and explanations?
Yes, every question includes the correct answer with a short explanation for revision.
4. How do these Heat MCQs help students?
They improve speed, accuracy, and strengthen important concepts like conduction, convection, and radiation.
5. What is the best way to practice this Heat MCQ set?
Solve all MCQs, review explanations, and repeat practice of weak areas for best results.
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