Ten questions. The result tells you which lessons you may skip.
A long straight wire carries \(10\,\text{A}\). The field \(5\,\text{cm}\) from it is
A short element of a current-carrying wire gives no magnetic field at a point
A long wire ends at O. On the perpendicular to the wire through O, at a distance \(d\), the field is
A single circular turn of radius \(0.1\,\text{m}\) carries \(5\,\text{A}\). The field at its centre is about
An arc of radius \(0.1\,\text{m}\) subtends \(60°\) at its centre and carries \(6\,\text{A}\). The field at the centre is about
On the axis of a circular loop of radius \(R\), at a distance \(\sqrt3 R\) from its centre, the field is
A long solid wire carries a current spread evenly over its cross-section. Its magnetic field is largest
A coaxial cable carries a current out along its core and back along its shell. The field just outside the cable is
A long solenoid has \(1000\) turns per metre and carries \(2\,\text{A}\). The field inside is about
The magnetic field in the hole at the centre of an ideal toroid is