Physics: Standard Level
The particulate nature of matter — Theme B
- 1.
A 0.50 kg metal block receives 9000 J of thermal energy and its temperature rises by 40°C. Calculate its specific heat capacity.
[3 marks] - 2.
Marking analysis: A learner attempts the following task: “A 0.50 kg metal block receives 9000 J of thermal energy and its temperature rises by 40°C. Calculate its specific heat capacity.” Their response addresses only this point: “Uses Q = mcΔT.” Evaluate the response against the complete 3-mark task. Identify what earns credit and state every additional requirement needed for full marks.
[3 marks] - 3.
A 0.20 kg sample of ice at 0°C absorbs 66 800 J of energy and fully melts. Calculate the specific latent heat of fusion of ice.
[3 marks] - 4.
Marking analysis: A learner attempts the following task: “A 0.20 kg sample of ice at 0°C absorbs 66 800 J of energy and fully melts. Calculate the specific latent heat of fusion of ice.” Their response addresses only this point: “Uses Q = mL.” Evaluate the response against the complete 3-mark task. Identify what earns credit and state every additional requirement needed for full marks.
[3 marks] - 5.
Explain, using the kinetic particle model, why the pressure of a fixed mass of gas increases when it is heated at constant volume.
[3 marks] · no calculator - 6.
Marking analysis: A learner attempts the following task: “Explain, using the kinetic particle model, why the pressure of a fixed mass of gas increases when it is heated at constant volume.” Their response addresses only this point: “States that heating increases the average kinetic energy (speed) of the gas particles.” Evaluate the response against the complete 3-mark task. Identify what earns credit and state every additional requirement needed for full marks.
[3 marks] · no calculator - 7.
A fixed mass of gas occupies 2.0 m³ at a pressure of 1.0 × 10⁵ Pa. It is compressed at constant temperature to a volume of 0.50 m³. Calculate the new pressure.
[3 marks] - 8.
Marking analysis: A learner attempts the following task: “A fixed mass of gas occupies 2.0 m³ at a pressure of 1.0 × 10⁵ Pa. It is compressed at constant temperature to a volume of 0.50 m³. Calculate the new pressure.” Their response addresses only this point: “States Boyle's law: p₁V₁ = p₂V₂ for constant temperature.” Evaluate the response against the complete 3-mark task. Identify what earns credit and state every additional requirement needed for full marks.
[3 marks] - 9.
A current of 3.0 A flows through a resistor for 5 minutes. Calculate the charge that flows and, given the resistor has resistance 4.0 Ω, the power dissipated.
[4 marks] - 10.
Marking analysis: A learner attempts the following task: “A current of 3.0 A flows through a resistor for 5 minutes. Calculate the charge that flows and, given the resistor has resistance 4.0 Ω, the power dissipated.” Their response addresses only this point: “Converts time to seconds: 5 × 60 = 300 s.” Evaluate the response against the complete 4-mark task. Identify what earns credit and state every additional requirement needed for full marks.
[4 marks] - 11.
Three 4.0 Ω resistors are connected in series with a 24 V battery. Calculate the current flowing and the voltage across each resistor.
[4 marks] - 12.
Marking analysis: A learner attempts the following task: “Three 4.0 Ω resistors are connected in series with a 24 V battery. Calculate the current flowing and the voltage across each resistor.” Their response addresses only this point: “Calculates total resistance for series resistors: 4.0 + 4.0 + 4.0 = 12.0 Ω.” Evaluate the response against the complete 4-mark task. Identify what earns credit and state every additional requirement needed for full marks.
[4 marks] - 13.
Two 6.0 Ω resistors are connected in parallel. Calculate their combined resistance.
[2 marks] - 14.
Marking analysis: A learner attempts the following task: “Two 6.0 Ω resistors are connected in parallel. Calculate their combined resistance.” Their response addresses only this point: “Uses 1/R = 1/6.0 + 1/6.0.” Evaluate the response against the complete 2-mark task. Identify what earns credit and state every additional requirement needed for full marks.
[2 marks] - 15.
Describe, in terms of particle arrangement and movement, the difference between a liquid and a gas.
[3 marks] · no calculator - 16.
Marking analysis: A learner attempts the following task: “Describe, in terms of particle arrangement and movement, the difference between a liquid and a gas.” Their response addresses only this point: “States that in a liquid, particles are close together with weak intermolecular forces, able to move past one another but not separate far.” Evaluate the response against the complete 3-mark task. Identify what earns credit and state every additional requirement needed for full marks.
[3 marks] · no calculator - 17.
A resistor of resistance R dissipates power P when connected to a fixed voltage V. Explain what happens to the power dissipated if the resistance is doubled, with V unchanged.
[3 marks] · no calculator - 18.
Marking analysis: A learner attempts the following task: “A resistor of resistance R dissipates power P when connected to a fixed voltage V. Explain what happens to the power dissipated if the resistance is doubled, with V unchanged.” Their response addresses only this point: “States the relation P = V²/R for power in terms of fixed voltage and resistance.” Evaluate the response against the complete 3-mark task. Identify what earns credit and state every additional requirement needed for full marks.
[3 marks] · no calculator - 19.
A gas at temperature 27°C and pressure 1.0 × 10⁵ Pa occupies a volume of 0.020 m³ in a sealed rigid container. It is heated to 127°C. Calculate the new pressure, assuming the volume is constant.
[4 marks] - 20.
Marking analysis: A learner attempts the following task: “A gas at temperature 27°C and pressure 1.0 × 10⁵ Pa occupies a volume of 0.020 m³ in a sealed rigid container. It is heated to 127°C. Calculate the new pressure, assuming the volume is constant.” Their response addresses only this point: “Converts both temperatures to kelvin: 27°C = 300 K, 127°C = 400 K.” Evaluate the response against the complete 4-mark task. Identify what earns credit and state every additional requirement needed for full marks.
[4 marks] - 21.
Calculate the number of moles of an ideal gas that occupies a volume of 0.0500 m³ at a pressure of 2.0 × 10⁵ Pa and a temperature of 300 K. Use R = 8.31 J K⁻¹ mol⁻¹.
[4 marks] - 22.
Marking analysis: A learner attempts the following task: “Calculate the number of moles of an ideal gas that occupies a volume of 0.0500 m³ at a pressure of 2.0 × 10⁵ Pa and a temperature of 300 K. Use R = 8.31 J K⁻¹ mol⁻¹.” Their response addresses only this point: “States the ideal gas equation: PV = nRT.” Evaluate the response against the complete 4-mark task. Identify what earns credit and state every additional requirement needed for full marks.
[4 marks] - 23.
A battery of EMF 12 V and internal resistance 0.50 Ω is connected to an external resistor of 5.5 Ω. Calculate the current in the circuit and the terminal voltage of the battery.
[5 marks] - 24.
Marking analysis: A learner attempts the following task: “A battery of EMF 12 V and internal resistance 0.50 Ω is connected to an external resistor of 5.5 Ω. Calculate the current in the circuit and the terminal voltage of the battery.” Their response addresses only this point: “States EMF = I(R + r), where R is the external resistance and r is the internal resistance.” Evaluate the response against the complete 5-mark task. Identify what earns credit and state every additional requirement needed for full marks.
[5 marks] - 25.
A potential divider circuit consists of two resistors, 20 Ω and 30 Ω, connected in series across a 10 V supply. Calculate the potential difference across the 30 Ω resistor.
[3 marks] - 26.
Marking analysis: A learner attempts the following task: “A potential divider circuit consists of two resistors, 20 Ω and 30 Ω, connected in series across a 10 V supply. Calculate the potential difference across the 30 Ω resistor.” Their response addresses only this point: “Uses the potential divider formula: V_out = V_in × (R₂/(R₁ + R₂)), taking R₂ as the resistor of interest.” Evaluate the response against the complete 3-mark task. Identify what earns credit and state every additional requirement needed for full marks.
[3 marks] - 27.
State what is meant by absolute zero, and describe what happens to the motion of gas particles as temperature approaches absolute zero.
[2 marks] · no calculator - 28.
Marking analysis: A learner attempts the following task: “State what is meant by absolute zero, and describe what happens to the motion of gas particles as temperature approaches absolute zero.” Their response addresses only this point: “States that absolute zero (0 K, −273°C) is the theoretical temperature at which a substance has minimum internal (kinetic) energy.” Evaluate the response against the complete 2-mark task. Identify what earns credit and state every additional requirement needed for full marks.
[2 marks] · no calculator - 29.
Describe an experiment to determine the specific heat capacity of a metal block using an electrical heater, stating the measurements needed and the equation used to calculate the result.
[5 marks] · no calculator - 30.
Marking analysis: A learner attempts the following task: “Describe an experiment to determine the specific heat capacity of a metal block using an electrical heater, stating the measurements needed and the equation used to calculate the result.” Their response addresses only this point: “States that an electrical heater is inserted into a hole in the metal block, with a thermometer used to measure the initial temperature.” Evaluate the response against the complete 5-mark task. Identify what earns credit and state every additional requirement needed for full marks.
[5 marks] · no calculator