6. (9%) (a) Two parallel wires carrying currents of 1.5 A of upward current (1) and 3 A of downward current (1) are placed 10 cm apart from each other. The wire with 1.5A current is located on the left as shown in Figure 4. 12 Figure 4. (i) What is the magnitude of the force per unit length exerted by one wire on the other? (ii) What is the total force exerted on the wire carrying 1.5 A current if its length is 50 cm? (3) (3) (b) A straight wire with a length of 24 cm carries a current of 5 A. The wire is making an angle of 45 to a uniform magnetic field of 3 T. What is the size of the magnetic force exerted on the wire? (3)