Answer:
[tex]4.61\times 10^{-5}\ \text{T}[/tex]
[tex]1.05\times 10^{-6}\ \text{Nm}[/tex]
Explanation:
[tex]\mu_0[/tex] = Vacuum permeability = [tex]4\pi10^{-7}\ \text{H/m}[/tex]
[tex]r_l[/tex] = Radius of loop = 15 cm
[tex]I_l[/tex] = Current in loop = 11 A
[tex]r_c[/tex] = Radius of coil = 0.76 cm
N = Number of turns of coil = 66
[tex]I_c[/tex] = Current in coil = 1.9 A
Magnetic field is given by
[tex]B=\dfrac{\mu_0I_l}{2r_l}\\\Rightarrow B=\dfrac{4\pi\times 10^{-7}\times 11}{2\times 0.15}\\\Rightarrow B=4.61\times 10^{-5}\ \text{T}[/tex]
Magnitude of magnetic field produced by the loop at its center is [tex]4.61\times 10^{-5}\ \text{T}[/tex].
Torque is given by
[tex]\tau=BI_c\pi r_c^2N\sin90^{\circ}\\\Rightarrow \tau=4.61\times 10^{-5}\times 1.9\times \pi\times (0.76\times 10^{-2})^2\times 66\sin90^{\circ}\\\Rightarrow \tau=1.05\times 10^{-6}\ \text{Nm}[/tex]
Magnitude of torque on the coil due to the loop is [tex]1.05\times 10^{-6}\ \text{Nm}[/tex]