10 questions · Form 2 Science Bab 9: Heat
What structural feature in a vacuum thermos flask prevents heat loss by both Conduction and Convection?
Prefer reading to quizzing? All 10 questions are listed below with the answer and explanation under each one.
1. What structural feature in a vacuum thermos flask prevents heat loss by both Conduction and Convection?
Answer: A
Conduction and convection both require a physical medium (particles) to transfer heat; a vacuum space eliminates particles, preventing both modes.
2. Which material is the best thermal conductor suitable for making the base of a frying pan?
Answer: C
Copper is a metallic conductor with high thermal conductivity, transferring heat quickly from burner flame to food.
3. Comparing the rates of thermal expansion for solids, liquids, and gases when exposed to equal temperature increases, which state expands the MOST?
Answer: C
Gas particles have the weakest intermolecular attraction forces, expanding significantly more than liquids or solids for a given temperature increase.
4. Why is mercury commonly used as the working fluid in traditional liquid-in-glass laboratory thermometers?
Answer: B
Mercury expands evenly and predictably over a wide temperature range, is easily visible, and does not wet glass capillary walls.
5. What is the SI unit for measuring heat energy?
Answer: A
Heat is a form of energy, so its standard SI unit is the Joule (J).
6. Which method of heat transfer can travel through a complete vacuum without requiring any physical medium?
Answer: C
Radiation transfers heat energy via electromagnetic waves, allowing heat from the Sun to travel through space vacuum.
7. Why are pot handles usually covered with plastic or wooden casing?
Answer: B
Plastic and wood are thermal insulators with low heat conductivity, keeping handles cool and safe to hold.
8. Which surface characteristics make an object the BEST absorber and radiation emission source of heat?
Answer: B
Dark, dull, and rough surfaces absorb radiant thermal energy most efficiently and emit thermal radiation fastest.
9. What phenomenon causes a sea breeze during daytime coastal weather?
Answer: B
During the day, land heats faster than sea water; rising warm air over land creates low pressure, pulling cooler air from the sea.
10. When two objects at different temperatures reach thermal equilibrium after being placed in contact, what condition must be true?
Answer: B
Thermal equilibrium is reached when two objects reach the same final temperature and the net rate of heat transfer between them is zero.