Magnetic flux and flux linkageAQA A-Level Physics: Flashcards

Exam questions on Magnetic flux and flux linkage

1. A flat circular coil of 200 turns and radius 3.0 cm is placed in a uniform magnetic field of flux density 0.040 T, with the plane of the coil perpendicular to the field direction.
   The coil is turned so that the normal to its plane makes an angle of 60° with the field. Calculate the flux linkage.2 marks
2. A student uses a small search coil connected to an oscilloscope to investigate how the magnetic flux linkage depends on orientation. The search coil is placed inside a long solenoid carrying a low-frequency alternating current from a signal generator. The search coil can be rotated so that the angle θ between its axis (the normal to its plane) and the field direction can be set to chosen values. For a fixed frequency, the peak-to-peak height of the oscilloscope trace is taken to be proportional to the peak flux linkage.
   With θ = 0° the peak-to-peak height is 48 mm. Predict the height when θ = 40°.2 marks
3. A rectangular coil of 150 turns measures 8.0 cm by 5.0 cm. It is placed in a uniform magnetic field of flux density 0.12 T.
   Calculate the flux linkage when the plane of the coil is perpendicular to the field, and when the plane of the coil makes an angle of 30° with the field direction.3 marks