Heat Transfer in Nature Part 1: MCQs (Q1–Q25)
📘 Chapter 7 – Heat Transfer in Nature
🔹 Part 1: Conduction (Q1–Q25)
Q1. Transfer of heat in solids mainly takes place by:
A) Convection
B) Conduction
C) Radiation
D) Evaporation
✅ Answer: B) Conduction
Explanation:
- Convection → in liquids/gases.
- Conduction → heat transfer in solids by particle vibration (Correct).
- Radiation → without medium.
- Evaporation → phase change, not heat transfer in solids.
Q2. Which of these is a good conductor of heat?
A) Plastic
B) Wood
C) Copper
D) Rubber
✅ Answer: C) Copper
Explanation:
Metals like copper, aluminium conduct heat well. Plastic, wood, rubber are insulators.
Q3. Which of these is a poor conductor of heat?
A) Silver
B) Iron
C) Aluminium
D) Wood
✅ Answer: D) Wood
Q4. Metals are good conductors because:
A) They are shiny
B) They have free electrons
C) They are malleable
D) They are ductile
✅ Answer: B) They have free electrons
Q5. Cooking utensils are made of metals because:
A) Metals conduct heat quickly
B) Metals are bad conductors
C) Metals are transparent
D) Metals prevent heating
✅ Answer: A) Metals conduct heat quickly
Q6. The handle of a cooking pan is made of plastic/wood because:
A) They look good
B) They are insulators
C) They are conductors
D) They are shiny
✅ Answer: B) They are insulators
Q7. Which of these is NOT a conductor?
A) Aluminium
B) Steel
C) Iron
D) Plastic
✅ Answer: D) Plastic
Q8. Which metal is the best conductor of heat?
A) Copper
B) Silver
C) Aluminium
D) Iron
✅ Answer: B) Silver
Q9. Which of these is used as an insulator?
A) Steel
B) Wool
C) Aluminium
D) Copper
✅ Answer: B) Wool
Q10. Heat transfer in a frying pan from the base to the handle is due to:
A) Radiation
B) Conduction
C) Convection
D) Evaporation
✅ Answer: B) Conduction
Q11. Why does a metal spoon become hot when kept in hot tea?
A) Convection
B) Radiation
C) Conduction
D) Reflection
✅ Answer: C) Conduction
Q12. Which of the following prevents heat loss by conduction?
A) Aluminium foil
B) Plastic coating
C) Iron sheet
D) Steel rod
✅ Answer: B) Plastic coating
Q13. Air is a poor conductor of heat because:
A) It has free electrons
B) Its particles are far apart
C) It is heavy
D) It is invisible
✅ Answer: B) Its particles are far apart
Q14. Liquids generally transfer heat by:
A) Radiation
B) Convection
C) Conduction
D) All of these
✅ Answer: B) Convection
Q15. Heat transfer by conduction requires:
A) Medium with free-moving particles
B) Direct contact between particles
C) No medium
D) Both A and B
✅ Answer: D) Both A and B
Q16. Which of these materials is used in making thermal flasks to reduce conduction?
A) Metal
B) Plastic
C) Glass with vacuum
D) Iron
✅ Answer: C) Glass with vacuum
Q17. In solids, particles transfer heat by:
A) Collisions and vibrations
B) Moving freely
C) Convection currents
D) Radiation
✅ Answer: A) Collisions and vibrations
Q18. Which of the following is NOT used as an insulator?
A) Wool
B) Rubber
C) Cotton
D) Copper
✅ Answer: D) Copper
Q19. The base of cooking utensils is made thick to:
A) Store more food
B) Distribute heat evenly
C) Make it heavier
D) Make it shiny
✅ Answer: B) Distribute heat evenly
Q20. Which of these metals is commonly used in cooking vessels?
A) Gold
B) Silver
C) Copper
D) Mercury
✅ Answer: C) Copper
Q21. An iron rod becomes hot from one end to the other because of:
A) Convection
B) Conduction
C) Radiation
D) Reflection
✅ Answer: B) Conduction
Q22. Which of these materials will feel colder on touching in winter?
A) Cotton cloth
B) Wooden table
C) Woollen cloth
D) Iron rod
✅ Answer: D) Iron rod
Explanation: Iron conducts heat away from hand faster, so feels colder.
Q23. Which of these prevents conduction of heat in thermos flasks?
A) Vacuum
B) Metal wall
C) Plastic lid
D) Silver coating
✅ Answer: A) Vacuum
Q24. Woollen clothes keep us warm in winter because:
A) Wool generates heat
B) Wool is a good conductor
C) Wool traps air (insulator)
D) Wool absorbs sunlight
✅ Answer: C) Wool traps air (insulator)
Q25. Which is the slowest method of heat transfer?
A) Radiation
B) Conduction
C) Convection
D) All are equal
✅ Answer: B) Conduction
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