Physics 9702: MAGNETIC FIELDS Topical Past Paper Questions

(a) State what is meant by an alternating current. [1] (b) A coil of wire is wound onto a hollow insulating tube to form a solenoid, as shown in Figure 7.1. Figure 7.1 There is a constant current $ I $ in the solenoid in the direction indicated. There is a magnetic field inside a…

A rectangular coil PQRS of wire is free to rotate about its axis XY, as shown in Fig. 6.1. Fig. 6.1 (not to scale) The coil has length QR of 5.4 cm, width PQ of 2.5 cm and has 190 turns of wire. The plane of the coil is at an angle $ \theta $ to a uniform magnetic field of flux d…

(a) Define magnetic flux density. [2] (b) A long, straight wire carries a current into the page, as shown in Fig. 7.1. Fig. 7.1 On Fig. 7.1, draw four field lines to represent the magnetic field around the wire due to the current in it. [3] (c) Two identical wires X and Y are pla…