Magnetic fields and forcesEdexcel A-Level Physics: Mind map

Exam questions on Magnetic fields and forces

1. A 0.12 m length of straight copper wire carries a steady current of 5.0 A. It lies horizontally at right angles to a uniform horizontal magnetic field of flux density 0.30 T between the flat poles of a large magnet.
   The wire is turned, in the horizontal plane, so that it makes an angle of 30° with the field lines. The current is unchanged. Calculate the force on the wire.2 marks
2. A proton enters a region of uniform magnetic field of flux density 0.050 T with a speed of 2.4 × 10⁶ m s⁻¹, moving at right angles to the field lines. The charge on a proton is 1.60 × 10⁻¹⁹ C and its mass is 1.67 × 10⁻²⁷ kg.
   Calculate the magnitude of the acceleration of the proton as it enters the field.2 marks
3. A flat rectangular coil of 250 turns measures 8.0 cm by 5.0 cm. It is placed in a uniform magnetic field of flux density 0.18 T, with the plane of the coil initially perpendicular to the field lines.
   Calculate the magnetic flux through the coil and the flux linkage of the coil, and state the unit of flux linkage.3 marks