Torque on a current loop in Earth's magnetic field

[ibaraku]

Homework Statement

A small current loop of area A = 1.5cm^2 carries current I = 3.6mA. What torque acts on it in a lab where its magnetic moment is perpendicualr to the Earth's magnetic field of
4.2 x 10^-5
(b) Find its angular acceleration if its rotational inertia about a diameter is 6.2gcm^2

Homework Equations

T = m x B
m = IA

The Attempt at a Solution

I know that m = (.015)(.0036) = 5.4 * 10^-5.

T = abs(5.4 * 10^-5) * abs(B) * Sin(PI/2)

I'm a bit confused about what B is, should I use the B for Earth's magnetic field?

 

[Redbelly98]

Yes, use the given B for the Earth's magnetic field.