Current of electricity — AS & A Level Physics (9702) questions by topic
Current of electricity questions in A Level Physics range from resistivity from a putty cylinder's dimensions to potentiometer circuits comparing two e.m.f.s and counting free electrons from a measured charge, worth from 1 to 12 marks.
State and explain sit alongside calculate and deduce among the top command words: state Ohm's law precisely, deduce which resistors share a current, then calculate resistivity or drift velocity. 50 real questions drawn from 2023 to 2025 papers are here. Submit each answer for instant marking so a missing constant-temperature condition or a mixed-up parallel formula gets flagged before it recurs across a whole circuits topic.
What examiners look for
- Examiners repeatedly note candidates cannot state Ohm's law fully, often giving a resistance equation without the idea of constant resistance at constant temperature.
- Reports flag the potentiometer circuit as poorly understood: many candidates cannot show the correct slider position or explain how it works.
- A recurring error is treating two fixed resistors in a circuit as parallel when they are actually in series.
- Common mistakes include substituting a velocity value for voltage, or omitting the cross-sectional area, when working from experimental data.
- Strong answers correctly recall the relevant symbol equation, and in 'show' questions set out the full calculation explicitly, not just the final answer.
May–June 2025, Paper 11
Which expression gives the definition of resistance? A current divided by potential difference B current multiplied by potential difference C potential difference divided by…
Answer this question and get it marked →Two resistors of resistances R₁ and R₂ are connected in parallel between terminals X and Y. What is the combined resistance between X and Y? A R₁ + R₂ B R₁R₂ / (R₁ + R₂) C (R₁ +…
Answer this question and get it marked →May–June 2025, Paper 12
A wire is made from a metal of constant resistivity. There is a constant current in the wire. Which statement about the potential difference across the wire is correct? A It is…
Answer this question and get it marked →A resistor of resistance 200 Ω is connected to a supply that has a p.d. of 4.00 V. How many electrons enter the resistor in 4.00 s? A 3.13 × 10^16 B 1.25 × 10^17 C 5.00 × 10^17 D…
Answer this question and get it marked →May–June 2025, Paper 13
The equation I = Anve gives the current I in a conductor, where A is the cross-sectional area, v is the mean drift velocity, and e is the elementary charge. What does n represent…
Answer this question and get it marked →Which charge could NOT be the charge on a charge carrier? A –4.8 × 10⁻¹⁹ C B –3.2 × 10⁻¹⁹ C C –2.4 × 10⁻¹⁹ C D –1.6 × 10⁻¹⁹ C
Answer this question and get it marked →A steel wire has resistivity ρ = 6.90 × 10⁻⁷ Ω m, length L = 2.20 m, and is connected to a supply of e.m.f. V = 1.50 V. The current in the wire is I = 4.90 A. What is the diameter…
Answer this question and get it marked →May–June 2025, Paper 14
The resistance of a lamp is 10 Ω and the potential difference across it is 6.0 V. How many electrons pass through the lamp in a time of 24 hours? A 5.2 × 10⁴ B 9.0 × 10¹⁹ C 5.4 ×…
Answer this question and get it marked →What is equivalent to one volt? A one coulomb per second B one joule per coulomb C one joule per second D one joule second per coulomb squared
Answer this question and get it marked →The resistance of some electrical components may change with changing conditions. Which component's resistance increases? A a filament lamp as the potential difference (p.d.)…
Answer this question and get it marked →Gold is sometimes used to make very small connecting wires in electronic circuits. A particular gold wire has length 2.50 × 10⁻³ m and cross-sectional area 6.25 × 10⁻⁸ m². Gold…
Answer this question and get it marked →May–June 2025, Paper 22
Define electric potential difference across a component.
Answer this question and get it marked →May–June 2025, Paper 23
A nichrome resistance wire has length 150 cm, cross-sectional area 2.45 × 10⁻⁷ m² and resistivity 1.12 × 10⁻⁶ Ω m. Calculate, to three significant figures, the resistance of the…
Answer this question and get it marked →May–June 2025, Paper 24
A filament lamp is connected in a circuit. As the current in the filament lamp decreases, state the effect on the resistance of the filament lamp.
Answer this question and get it marked →May–June 2024, Paper 11
What is the unit of resistivity? A Ω m⁻² B Ω m⁻¹ C Ω D Ω m
Answer this question and get it marked →A kettle is connected to a 250 V mains supply. What are possible values for the power of the kettle and the current in the kettle? power / W current / A --- --- --- A 500 0.5 B…
Answer this question and get it marked →May–June 2024, Paper 12
What is the definition of potential difference across a component? A energy transferred per unit charge B energy transferred per unit current C energy transferred per unit…
Answer this question and get it marked →The I–V characteristics for four components, A, B, C and D, are shown on a current against voltage graph; at voltage V₁ the curves are ordered A (highest current), then B, then C,…
Answer this question and get it marked →A cylindrical wire has cross-sectional area A and number density of free electrons n. The wire has current I and the free electrons have average drift speed v. A second…
Answer this question and get it marked →An electric current is formed by moving charge carriers. What is not a possible charge on a charge carrier? A −4.8 × 10⁻¹⁹ C B −2.4 × 10⁻¹⁹ C C +1.6 × 10⁻¹⁹ C D +3.2 × 10⁻¹⁹ C
Answer this question and get it marked →May–June 2024, Paper 13
Which quantity is given by the product of charge and electric potential difference? A current B energy transferred C power dissipated D resistance
Answer this question and get it marked →The current in a filament lamp is increased. Which statement about the lamp is correct? A The brightness of the lamp decreases. B The potential difference across the filament…
Answer this question and get it marked →The resistance of a metal cube is measured by placing it between two parallel plates, as shown. The cube has volume V and is made of a material with resistivity ρ. The connections…
Answer this question and get it marked →October–November 2024, Paper 12
The potential difference V across a filament lamp is slowly raised from zero to its normal operating value. Which graph represents the variation with V of the current I in the…
Answer this question and get it marked →An electric current of 12 A is in a wire of length 0.35 m. The average drift speed of the free electrons (charge carriers) in the wire is 5.0 x 10^-4 m s^-1. How many free…
Answer this question and get it marked →October–November 2024, Paper 13
Two identical balls are projected vertically upwards from ground level with the same initial velocity. Ball X is in a vacuum and ball Y is in air. Which statement about the motion…
Answer this question and get it marked →A tennis ball is thrown vertically upwards. The tennis ball reaches its highest point and then falls back down to the point from which it was thrown. Air resistance is…
Answer this question and get it marked →What is an electric current? A a flow of charge carriers B a flow of energy C an electron D the charge on a particle
Answer this question and get it marked →A wire of diameter d is connected into an electric circuit. There is a current I in the wire and the charge carriers have an average drift speed v. The wire is replaced with a new…
Answer this question and get it marked →A fixed resistor and a diode are combined by connecting them in series. The total potential difference V across the combination is varied and the corresponding current I is…
Answer this question and get it marked →October–November 2024, Paper 23
February–March 2023, Paper 12
Which graph represents the way the current I through a filament lamp varies with the potential difference V across it? A I increases with V with an increasing gradient. B I…
Answer this question and get it marked →The table shows the properties of two different wires, P and Q. Wire P has length l, resistance R and resistivity rho. Wire Q has length 2l, resistance R/4 and resistivity rho/3.…
Answer this question and get it marked →May–June 2023, Paper 11
The electric current in a metal wire is 4.0 mA. How many electrons pass a fixed point in the wire in a time of 10 hours? A 2.5 x 10^17 B 2.5 x 10^20 C 9.0 x 10^20 D 9.0 x 10^23
Answer this question and get it marked →Which graph shows the I-V characteristic of a filament lamp? A I stays near zero then rises very steeply at high V. B I increases linearly with V (straight line through origin). C…
Answer this question and get it marked →A metal wire has a length of 2.50 m and a cross-sectional area of 4.50 x 10^-6 m^2. The resistivity of the metal is 3.50 x 10^-7 ohm m. The wire is stretched so that its length…
Answer this question and get it marked →May–June 2023, Paper 12
A box in air slides with increasing speed down a rough slope from point P to point Q. The slope surface exerts a constant frictional force on the box. As the box moves from P to…
Answer this question and get it marked →An electrical cable is made up of one thick strand of copper wire that is surrounded by eight thin strands of copper wire. All nine strands of wire are connected in parallel with…
Answer this question and get it marked →May–June 2023, Paper 13
A metal wire is connected between the terminals of a cell so that there is a current in the wire. Which statement is correct? A Negatively charged electrons in the wire move from…
Answer this question and get it marked →A wire has a length of 3.0 m and is made of metal of resistivity 4.9 x 10^-7 ohm m. A potential difference (p.d.) of 12 V is applied across the wire so that it has a current of…
Answer this question and get it marked →May–June 2023, Paper 21
A metal wire in a circuit has a length of 1.8 m and a cross-sectional area of 1.5 x 10^-6 m^2. The total number of free electrons (charge carriers) in the wire is 2.3 x 10^23.…
Answer this question and get it marked →May–June 2023, Paper 22
The current in a filament lamp decreases. State and explain how the resistance of the lamp changes.
Answer this question and get it marked →October–November 2023, Paper 11
The current I in a conductor is given by the equation I = Anvq. What does the letter n represent in this equation? A charge carried per charge carrier B number of charge carriers…
Answer this question and get it marked →Which graph could show how the resistance R of a filament lamp varies with the applied potential difference (p.d.) V, as V is increased to the normal operating p.d.? The options A…
Answer this question and get it marked →A piece of conducting putty is in the shape of a cylinder of length 60 mm and diameter 20 mm. The resistance between the ends of the cylinder is 20 ohm. What is the resistivity of…
Answer this question and get it marked →October–November 2023, Paper 12
The potential difference across a metal wire is kept constant. The length l and the diameter d of the wire are both varied. The type of metal is kept the same. How is the current…
Answer this question and get it marked →October–November 2023, Paper 13
What could not be used to create an electric current? A alpha-particles B beta-particles C neutrons D protons
Answer this question and get it marked →The resistance of a filament lamp increases as the current in it increases. What is the reason for this? A The charge of each charge carrier increases. B The potential difference…
Answer this question and get it marked →October–November 2023, Paper 22
A metal wire has a resistance per unit length of 0.92 ohm m^-1. The wire has a uniform cross-sectional area of 5.3 x 10^-7 m^2. Calculate the resistivity of the metal of the wire.
Answer this question and get it marked →October–November 2023, Paper 23
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