Question 1: Define conduction and give an example of where it occurs in everyday life.

Answer: Conduction is the transfer of heat through direct contact between particles, such as a metal spoon heating up in a hot cup of tea.

Question 2: Explain how convection transfers heat in a fluid or gas, and provide a practical example.

Answer: Convection transfers heat through the movement of fluid or gas particles, creating currents; for example, warm air rising and cool air sinking in a room.

Question 3: Describe how radiation transfers heat, and name a common example.

Answer: Radiation transfers heat through electromagnetic waves, such as the Sun warming the Earth.

Question 4: Which method of heat transfer does not require a medium (like air or water) to occur?

Answer: Radiation

Question 5: Fill in the blank: Heat transfer through direct contact between particles is called ________.

Answer: conduction

Question 6: List two materials that are good conductors of heat and explain why.

Answer: Materials like copper and aluminum are good conductors because they have free electrons that transfer heat efficiently.

Question 7: Describe an experiment to demonstrate convection in water.

Answer: Heat water in a transparent container and observe how the warmer water rises while cooler water sinks, creating convection currents. Use a thermometer to record temperature changes at different depths.

Question 8: A piece of metal is heated at one end; describe how heat is transferred along the metal.

Answer: Heat is transferred along the metal through conduction, as particles vibrate and pass energy to neighboring particles.

Question 9: Calculate the amount of heat transferred if 500 grams of water is heated from 20°C to 80°C. (Specific heat capacity of water = 4.18 J/g°C).

Answer: Q = mcΔT = 500 g × 4.18 J/g°C × (80°C - 20°C) = 500 × 4.18 × 60 = 125,400 Joules.

Question 10: Identify an appliance or device that uses radiation to transfer heat and explain how it works.

Answer: A microwave oven uses microwave radiation to excite water molecules in food, transferring heat internally.

Question 11: Explain the importance of understanding different heat transfer methods in designing insulation for buildings.

Answer: Understanding conduction, convection, and radiation helps in selecting appropriate insulation materials and designs to minimize heat loss or gain, improving energy efficiency and comfort.