Free Current, p.d. & resistance questions for IGCSE Physics (0625), part of Electricity & magnetism. Each question has the answer and the marking points an examiner would look for.
Generate a full Current, P.d. & Resistance worksheet →All Electricity & magnetism questionsTwo identical lamps X and Y are connected in series with a battery. A third identical lamp Z is then connected in parallel with lamp Y, as shown.
How do the brightnesses of X and Y change when Z is connected?
| lamp X | lamp Y | |
|---|---|---|
| A | brighter | brighter |
| B | brighter | dimmer |
| C | no change | dimmer |
| D | dimmer | dimmer |
Answer: B
Fig. shows the reading on an ammeter. What is the current?
Answer: B
Two resistors of 4.0 Ω and 12 Ω are connected in parallel to a 6.0 V battery.
Calculate the combined resistance.
Calculate the current from the battery.
State why the combined resistance is less than either resistor.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | 3.0 Ω 1/R = 1/4 + 1/12 C1 3.0 Ω A1 | 2 |
| (b) | 2.0 A I = V ÷ R = 6.0 ÷ 3.0 C1 2.0 A A1 | 2 |
| (c) | more paths for current there are more paths for the current to flow B1 | 1 |
A lamp draws a current of 0.30 A from a 3.0 V supply.
Define electric current.
Calculate the resistance of the lamp.
Calculate the charge that passes through the lamp in 60 s.
Use your answer to (c) to calculate the energy transferred by the lamp in this time.
Sketch the current–voltage graph for a filament lamp and explain its shape.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | rate of flow of charge the rate of flow of (electric) charge B1 | 1 |
| (b) | 10.0 Ω R = V/I C1 10.0 Ω A1 | 2 |
| (c) | 18.0 C Q = It = 0.30 × 60 C1 18.0 C A1 | 2 |
| (d) | 54.0 J E = QV = 18.0 × 3.0 C1 54.0 J A1 | 2 |
| (e) | curve, gradient decreasing; filament heats up, resistance increases curve through origin with decreasing gradient (S-shape for both directions) B1 as current increases the filament gets hotter B1 resistance increases (ions vibrate more) B1 | 3 |
Lamps in a house are connected in parallel rather than in series.
Give two advantages of connecting the lamps in parallel.
In a series circuit, describe how the current at different points compares.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | independent switching; full voltage Any 2 of: each lamp can be switched on and off independently; each lamp gets the full supply voltage; if one lamp fails the others stay on B2 | 2 |
| (b) | same everywhere the current is the same at every point B1 | 1 |
This question is about electric charge.
A polythene rod is rubbed with a cloth and becomes negatively charged. Explain how it becomes charged.
A charge of 24 C flows through a lamp in 8 s. Calculate the current.
State the difference between conductors and insulators in terms of electrons.
Explain why a fuel tanker is connected to the ground with a wire before fuel is pumped.
Define electric field and state the direction of the field lines around a positive point charge.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | electrons transferred from cloth to rod electrons are transferred (by friction) B1 from the cloth to the rod B1 | 2 |
| (b) | 3.00 A I = Q/t = 24/8 C1 3.00 A A1 | 2 |
| (c) | conductors have free electrons; insulators do not conductors contain free (delocalised) electrons that can move B1 insulators have no free electrons B1 | 2 |
| (d) | fuel flow can build up static charge; spark could ignite fuel; wire lets charge flow to earth Any 2 of: friction from the flowing fuel can build up charge; a spark could ignite the fuel vapour; the wire lets charge flow safely to earth B2 | 2 |
| (e) | region where a charge experiences a force; radially outwards a region in which an electric charge experiences a force B1 field lines point radially outwards from a positive charge B1 | 2 |
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Meet Riyaz →Original Cambridge-style practice questions written for mentorriyaz.in. These are not Cambridge past paper questions, and this site is not affiliated with or endorsed by Cambridge University Press & Assessment. Updated 2026-11-04. Paper generator · mentorriyaz.in