Use a sharp pencil and a ruler. Field lines must never cross or touch, and every line needs an arrow showing its direction (north to south). Tap 🔍 See examples to see how the diagram usually looks – pictures online vary, so if one disagrees with the instructions, follow the instructions. ← All key diagrams
85. Field around a bar magnet
Draw a rectangle labelled N at one end and S at the other. Draw curved field lines looping from the N pole round to the S pole on both sides, with arrows pointing from N to S. Draw the lines closer together near the poles. Label: “field lines go from north to south”, “field strongest at the poles – lines closest together”.
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86. Attracting and repelling magnets
Draw two pairs of bar magnets. Attracting: N facing S with a small gap, and straight field lines going across the gap from N to S. Repelling: N facing N, with field lines from each pole bending away from each other and a neutral point in the middle where no lines go. Label: “unlike poles attract”, “like poles repel”, “neutral point”.
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87. Plotting a field with a compass
Draw a bar magnet on a sheet of paper. Draw a small plotting compass near the N pole with its needle drawn as an arrow. Mark a dot where the needle points, then draw the compass moved to that dot, and repeat three times. Join the dots with a smooth curve ending at the S pole. Label: “mark where the needle points”, “move the compass to the dot and repeat”, “join the dots to make a field line”.
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88. Field around a straight wire
Draw a vertical wire passing through a horizontal card, with an arrow on the wire showing the current direction. Draw three circles on the card around the wire, spaced further apart as they get further out, each with an arrow showing the field direction. Label: “concentric circles”, “field is stronger closer to the wire”, “reversing the current reverses the field”.
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89. Field around a solenoid
Draw a coil of wire as a row of loops, with the ends connected to a battery. Inside the coil, draw straight, parallel, evenly spaced field lines. Outside, draw lines looping from one end to the other, like a bar magnet. Mark N at one end and S at the other. Label: “inside – strong and uniform field”, “outside – like a bar magnet”.
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90. Electromagnet
Draw a solenoid wrapped around an iron bar, connected to a battery and a switch. Draw paper clips attracted to one end. Label: “iron core – increases the field strength”, “coil of wire”, “switch – can be turned on and off”. Write: “stronger with more current or more turns”.
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91. Electric bell (S only)
Draw a circuit with a battery and a push switch connected to an electromagnet. Draw an iron armature on a spring next to the electromagnet, with a hammer on the end next to a bell (gong). Draw a contact screw touching the armature. Label: electromagnet, iron armature, spring, hammer, gong, contact. Write: “current flows → armature attracted → hammer hits bell → circuit breaks → spring pulls armature back → repeats”.
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92. Fleming’s left-hand rule (HT)
Draw your left hand with your thumb, first finger and second finger all at right angles to each other. Label: “thuMb = Motion (force)”, “First finger = Field (N to S)”, “seCond finger = Current (+ to −)”. Next to it, draw a wire between N and S poles with the current direction and the resulting force arrow.
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93. Electric motor (HT)
Draw a rectangular coil between an N pole on the left and an S pole on the right. Connect the coil ends to a split-ring commutator at the front, with two carbon brushes touching it and wires to a battery. Draw the current direction on the coil, and a force arrow up on one side and down on the other. Label: magnet, coil, split-ring commutator, brushes, “forces in opposite directions make the coil rotate”, “commutator reverses the current every half turn”.
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94. Loudspeaker (S only, HT)
Draw a cross-section: a permanent magnet at the back, a coil of wire around its centre, and a paper cone attached to the coil, opening to the right. Draw wires from the coil to an a.c. supply. Draw sound waves coming from the cone. Label: “a.c. in the coil”, “force keeps changing direction (motor effect)”, “coil and cone vibrate”, “produces sound waves”.
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95. Alternator and its output (S only, HT)
Draw a rectangular coil between N and S poles, turned by a handle. Connect each end of the coil to its own slip ring, with a brush on each, leading to a lamp. Next to it, draw a graph of “induced p.d.” against “time” showing a smooth wave above and below the axis. Label: “slip rings”, “brushes”, “a.c. output”, “faster rotation → higher peaks and more waves per second”.
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96. Transformer (S only, HT)
Draw a square iron core. Wrap a coil with a few turns around the left side and a coil with more turns around the right side. Connect the left coil to an a.c. supply and the right coil to a lamp. Label: “primary coil”, “secondary coil”, “iron core – easily magnetised”, “step-up – more turns on the secondary”, “Vp ÷ Vs = np ÷ ns”.
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Check your drawings: Magnetism topic page | Magnets and magnetic fields | Electromagnets and solenoids | Teach the topic: Magnetism
