Answer:
The torque in the coil is  4.9 Ă 10â»â” N.m Â
Explanation:
T = NIABsinΞ
Where;
T is the  torque on the coil
N is the number of loops = 9
I is the current = 7.8 A
A is the area of the circular coil = ?
B is the Earth's magnetic field = 5.5 Ă 10â»â” T
Ξ is the angle of inclination = 90 - 56 = 34°
Area of the circular coil is calculated as follows;
[tex]A = \frac{\pi d^2}{4} \\\\A = \frac{\pi 0.17^2}{4} =0.0227 m^2[/tex]
T = 9 Ă 7.8 Ă 0.0227 Ă 5.5Ă10â»â” Ă sin34°
T = 4.9 Ă 10â»â” N.m
Therefore, the torque in the coil is  4.9 Ă 10â»â” N.m