Magnetic Fields in Wires Flashcards
All 5 cards in this deck
What are the steps to use iron filings to show the shape of the magnetic field produced by a current?
e.g. a straight wire passing vertically through a horizontal card- Sprinkle iron filings over the card (before switching the current on).
- Switch on the current and tap the card.
- The pattern produced shows the shape of the field — circles around the wire.
What is the shape of the magnetic field produced by a current in a long straight conductor?
Concentric circles centred on the wire, with the circles getting further apart further from the wire.
Direction is given by the right-hand grip rule.True or false? When a current flows in a straight wire, a nearby plotting compass needle points straight at the wire.
False. The needle lies tangential to the circular magnetic field lines around the wire.
What two things does the strength of the magnetic field around a long straight conductor depend on?
The size of the current (bigger current = stronger field) and the distance from the wire (further away = weaker field).
Stronger field is shown by field lines closer together.How do you use the right-hand grip rule to find the direction of the magnetic field around a straight wire?
Grip the wire with your right hand, thumb pointing in the direction of the current. Your curled fingers show the direction of the field lines.