A student is investigating the magnetic effect of an electric current. She has a length of insulated copper wire, a cell, a switch, a plotting compass and some iron filings on a stiff card.
Describe how the student could use some of this equipment to demonstrate that a current in a wire produces a magnetic field.
State two factors that affect the strength of the magnetic field at a point near a straight current-carrying wire.
Figure 1 shows the magnetic field pattern around a long straight wire. The wire is at right angles to the page and the current in the wire is out of the page.
Describe the magnetic field pattern shown in Figure 1.
The direction of the current in the wire is reversed. Describe the effect this has on the magnetic field.
When Fleming's left-hand rule is used, which quantity does the second finger represent?
Tick one box.
A straight wire is held at right angles to the magnetic field between the poles of a magnet. A current is passed through the wire and a force acts on the wire.
State two changes that would increase the size of this force.
