IB DP Physics Questions

8.2 Thermal Energy Transfer

Question 1

Which mode of heat transfer primarily occurs in solids due to the vibration of particles?

A. Convection

B. Radiation

C. Conduction

D. Reflection

Question 2

Which of the following is NOT a greenhouse gas?

A. Carbon dioxide

B. Methane

C. Nitrogen

D. Water vapour

Question 3

In which medium does convection primarily occur?

A. Solids

B. Liquids

C. Gases

D. Both B and C

Question 4

Which property determines the amount of energy radiated by a black body in terms of its temperature?

A. Stefan's Law

B. Newton's Law

C. Ohm's Law

D. Boyle's Law

Question 5

Which factor does NOT affect the rate of conduction in a material?

A. Temperature difference

B. Material's state

C. Cross-sectional area

D. Colour of the material

Question 6

a) Explain the process of conduction and how it results in heat transfer in solids. [3]

b) A metal rod of length 1.5m and cross-sectional area 0.002 m^2 has a temperature difference of 20°C between its ends. If the thermal conductivity of the metal is 400 W/(m·K), calculate the rate of heat transfer through the rod. [3]

Question 7

a) Describe the mechanism of convection currents in fluids and their significance in various natural phenomena. [3]

b) A container has water heated from below. If the temperature difference between the bottom and top of the container is 25°C and the height of the water column is 0.5m, calculate the change in density of the water due to this temperature difference. (Assume the volume expansion coefficient of water is 0.000214 1/°C) [3]

Question 8

a) Explain the concept of electromagnetic radiation as a mode of heat transfer. [3]

b) An object at a temperature of 500K emits radiation with a peak wavelength of 5.8 x 10^-6 m. Using Wien's displacement law, calculate the constant. [3]

Question 9

a) Describe the factors that affect the rate of heat transfer through conduction in solids. [3]

b) A copper rod and an aluminium rod of the same dimensions are placed end to end. If the copper rod conducts heat at a rate of 400 W and the aluminium rod conducts heat at a rate of 200 W, which rod will have a higher temperature gradient? [2]

c) How does the temperature gradient relate to the rate of heat transfer in solids? [2]

Question 10

a) Explain the principle behind the formation of convection currents in the Earth's mantle. [3]

b) How do convection currents in the Earth's mantle influence tectonic plate movements? [3]

c) Why are convection currents more prominent in fluids compared to solids? [2]