Unit 2: The Particulate Nature of Matter
Topic 2.5: Current and Circuits Questions
Practice 20 exam-style questions for IB Physics SL Topic 2.5. Review the question stems below, then unlock the full Question Bank to access markschemes, model answers, and AI grading.
1Calculate1 mark
2026
At 40 °C, 0.80 m of wire with a 1.2 × 10−8 m2 cross-section measures 3.2 Ω.
Calculate the alloy's resistivity at that temperature.
Calculate the alloy's resistivity at that temperature.
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Unlock Question2Show that2 marks
2026
A 9.0 V supply with no internal resistance feeds a 150 Ω resistor, followed by a fixed resistor and a thermistor side by side. A meter across the side-by-side pair shows 3.0 V.
Show that 40 mA flows from the supply.
Show that 40 mA flows from the supply.
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Unlock Question3State1 mark
2026
An ideal voltmeter is connected across a lamp. State the current in the voltmeter.
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2026
A thermistor at 15 °C has a pd of 4.5 V across it and a current of 1.8 mA in it.
Calculate its resistance.
Calculate its resistance.
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2026
A kettle element works at 230 V with a current of 8.0 A for 120 s.
Calculate the thermal energy transferred.
Calculate the thermal energy transferred.
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Unlock Question6Show that1 mark
2026
Show that the combined resistance is 2.0 Ω.
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Unlock Question7Determine2 marks
Two resistors, 5.0 Ω and 15 Ω, are connected in series with a cell of negligible internal resistance.
The current in the circuit is 0.40 A.
Determine the emf of the cell.
The current in the circuit is 0.40 A.
Determine the emf of the cell.
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Unlock Question8Determine2 marks
2025
A loop holds a battery (no internal resistance), a 30 Ω resistor and a lamp whose resistance is 15 Ω at the loop current of 0.20 A.
Determine the battery's emf.
Determine the battery's emf.
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Unlock Question9Determine2 marks
2025
A 25 Ω resistor and component Q share a single loop with a battery of no internal resistance. The loop current is 80 mA, and Q has 1.8 V across it.
Determine the battery's emf.
Determine the battery's emf.
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Unlock Question10Calculate2 marks
2026
An LDR of resistance 1.5 kΩ in bright light is in series with a 4.5 kΩ resistor and a 12 V cell of negligible internal resistance.
Calculate the current in bright light.
Calculate the current in bright light.
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Unlock Question11Explain1 mark
2026
An LDR is in series with a resistor and a cell of negligible internal resistance. The room becomes darker.
Explain the change in the power transferred from the cell.
Explain the change in the power transferred from the cell.
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2026
A thin filament lamp is connected in series with thick copper leads. The current in the leads is 0.40 A.
What is the current in the filament?
What is the current in the filament?
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2026
A 1.50 m length of heating wire, 2.0 × 10−7 m2 in cross-section, measures 8.25 Ω.
Calculate the resistivity of the alloy it is made from.
Calculate the resistivity of the alloy it is made from.
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Unlock Question14Calculate2 marks
2026
An LDR of resistance 300 kΩ in darkness is in series with a 100 kΩ resistor and an 8.0 V cell of negligible internal resistance.
Calculate the current in darkness.
Calculate the current in darkness.
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State what is meant by the emf of a cell.
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Identify whether the current or the potential difference is the same for two resistors connected in parallel, and state which resistor — the larger or the smaller — carries the greater current.
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2025
Identical resistors, each R, are wired three ways. P: two end to end. Q: two side by side. S: one followed by a side-by-side pair.
Which list goes from least to most total resistance?
Which list goes from least to most total resistance?
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2026
An ideal voltmeter is used to measure the pd across a lamp. State the property of the voltmeter that makes it ideal.
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2025
A 40 Ω resistor and a lamp are joined one after the other to a battery with no internal resistance. The loop current is 0.15 A and the lamp has 2.5 V across it.
Determine the battery's emf.
Determine the battery's emf.
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Unlock Question20Outline1 mark
2025
The I–V graph of a filament lamp bends towards the voltage axis at higher voltages.
Outline how the resistance of the lamp changes as the current in it increases.
Outline how the resistance of the lamp changes as the current in it increases.
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