Question A7 A wire ring of radius a, is placed in an external uniform magnetic field as shown in figure 4 B = B₂₁+ B₂j where B < 0 and By < 0, and carrying a clock-wise current I. a) Apply the right-hand rule and find the direction of the magnetic moment vector, . b) Derive an expression for the magnitude of the torque on the loop. X Figure 4: A wire ring in an external magnetic field - [1 marks [4 marks

Question A7 A wire ring of radius a, is placed in an external uniform magnetic field as shown in figure 4 B = B₂₁+ B₂j where B < 0 and By < 0, and carrying a clock-wise current I. a) Apply the right-hand rule and find the direction of the magnetic moment vector, . b) Derive an expression for the magnitude of the torque on the loop. X Figure 4: A wire ring in an external magnetic field - [1 marks [4 marks