29:41.923Z","modelVersion":"gpt-5.6-terra+diagrams-1","explanationVersion":"v3"},"options":[]},{"id":"36391518-75e3-4a42-b7d3-b988029e14ce","label":"b","content":"The diagram shows a straight wire positioned in the magnetic field between the South pole (on the left) and the North pole (on the right) of a magnet.\n\n![A U-shaped magnet with its South pole on the left and North pole on the right. A straight wire passes through the gap between these poles from the front toward the back. The wire is connected in a circuit with a battery and a switch. The battery's positive terminal is on the left and the negative terminal is on the right, so conventional current flows from the positive terminal, through the wire from front to back, and back to the negative terminal when the switch is closed.](https://assets.mathsgenie.co.uk/aqa-qb/d3434d55-b8b9-4de4-96f6-254c64578798.png)\n\nDescribe and explain what happens to the wire when the switch is closed.","markscheme":"- Explains that closing the switch causes conventional current to flow from front to back, creating its own magnetic field around the wire B1\n- Explains that this magnetic field interacts with the permanent magnetic field which points from North (right) to South (left) B1\n- Concludes that the wire experiences a force and moves **upwards** (by applying Fleming's Left Hand Rule) A1","marks":3,"order":1,"markingRubric":null,"explanation":{"methods":[{"id":"motor_effect","label":"Motor effect explanation","steps":[{"type":"text","order":0,"title":"Trace the current","content":"Closing the switch completes the circuit, so **conventional current** flows through the wire from the front towards the back. A current-carrying wire produces its own magnetic field around it.\n\nThis explanation earns the first **B1** mark.","highlights":[{"text":"when the switch is closed","location":"specification"}]},{"type":"text","order":1,"title":"Identify the magnet field","content":"Magnetic field lines outside a magnet go from **North to South**. Here the North pole is on the right and the South pole is on the left, so the permanent magnetic field across the gap points from right to left.\n\nThe wire’s magnetic field and the permanent magnetic field interact. This earns the second **B1** mark.","highlights":[{"text":"South pole (on the left) and the North pole (on the right)","location":"specification"}]},{"type":"text","order":2,"title":"Apply the hand rule","content":"Use **Fleming’s Left-Hand Rule**:\n\n- first finger: magnetic **field**, from right to left;\n- second finger: conventional **current**, from front to back (into the page);\n- thumb: the **force** on the wire.\n\nYour thumb points **upwards**. Therefore the wire experiences a force and moves upwards. This conclusion earns the **A1** mark.","highlights":[{"text":"Describe and explain what happens to the wire when the switch is closed.","location":"specification"}]}]}],"generatedAt":"2026-07-22T09:07:25.719Z","modelVersion":"gpt-5.6-terra+diagrams-1","explanationVersion":"v3"},"options":[]},{"id":"a4823ca6-1104-41d4-9b0c-fe26ae406c7f","label":"c","content":"A current of \$3.5\\text{ A}\$ passes through a wire with a length of \$0.80\\text{ m}\$.\n\nThe wire is in a magnetic field of magnetic flux density \$0.45\\text{ T}\$.\n\nCalculate the force acting on the wire.\n\nGive your answer to 2 significant figures.","markscheme":"- Selects or uses the force formula $F = BIL$ C1\n- Substitutes the given values: $F = 0.45 \\times 3.5 \\times 0.80$ M1\n- Calculates the force as $1.26\\text{ N}$ and rounds to 2 significant figures to obtain $1.3\\text{ N}$ A1","marks":3,"order":2,"markingRubric":null,"explanation":{"methods":[{"id":"magnetic_force","label":"Use the magnetic force formula","steps":[{"type":"text","order":1,"title":"Choose the formula","content":"For this calculation, use $$F=BIL$$ where $F$ is force, $B$ is magnetic flux density, $I$ is current and $L$ is wire length. This is the form used when the wire is perpendicul

	Primary coil p.d. ( $V\text{V}$ )	Primary coil Current ( $A\text{A}$ )	Secondary coil p.d. ( $V\text{V}$ )	Secondary coil Current ( $A\text{A}$ )
A	240	2	120	4
B	120	4	240	2
C	240	2	120	6
D	240	2	240	2

	Primary coil p.d. ( $V\text{V}$ )	Primary coil Current ( $A\text{A}$ )	Secondary coil p.d. ( $V\text{V}$ )	Secondary coil Current ( $A\text{A}$ )
A	240	2	120	4
B	120	4	240	2
C	240	2	120	6
D	240	2	240	2

Uses of magnetism

Question 7

Uses of magnetism Questions

Uses of magnetism

Question 7

Uses of magnetism Questions