Checkpoint: fields, coils and wires

What shape are the field lines round a straight current-carrying wire?

• Lines from a north pole to a south pole
• Straight lines along the wire
• Rings round the wire

Field lines are crowded together at one place. What does this show?

• There is no field there
• The field is stronger there
• The field is weaker there

How can you make a coil magnet stronger?

• Wind the turns far apart
• Add more turns
• Switch the current off

A wire that carries current sits in a magnetic field. When is the push biggest?

• When the wire is square to the field
• When the wire is at 45° to the field
• When the wire is along the field

A loop is seen from the front. The current goes anticlockwise. Which way does the field point through it?

• Away from you
• Towards you
• Along the wire

A flexible cord uses brown for live. Which colour then marks the neutral wire?

• Green and yellow
• Blue
• Brown