10. A rectangular coil consists of N = 1000 closely wrapped turns and has dimensions a = 0.400 m and b = 0.300 m. The coil is hinged along the y axis, and its plane makes an angle θ = 30.0° with the x axis (Fig. 6). (a) What is the magnitude of the torque exerted on the coil by a uniform magnetic field B = 0.800 T directed in the positive x direction when the current is I = 1.20 A in the direction shown? (8 points) (b) What is the expected direction of rotation of the coil? (2 points) (以科學記號表示且四捨五入至小數點 3 位)