Question

A 2 cm long metal wire is formed into a rectangle (long side is 3x the short side) and placed in the horizontal xy-plane. A uniform magnetic field is oriented at 30 degrees above the horizontal with a strength of 0.32 T. The magnetic flux through the rectangle is:

A) 5.0x10^-6 Wb B) 5.0x10^-2 Wb C) 3.0x10^-6 Wb D) 3.0x10^-2 Wb E) 0

Explain why you chose that answer.

Answer 1

Given,

Length, L = 2 cm = 0.02 m

Circumference of the rectangle, S = L

2(3a + a) = L

side of the rectangle, a = L / 8 = 0.0025 m and b = 0.0075 m

Area of the rectangle, A = a x b = 1.875 x 10^-5 m²

Magnetic field, B = 0.32 T

Angle, = 30°

The magnetic flux through the square due to this field = BA cos (90- ) = BA cos 60° = 3 x 10^-6 Wb

Correct answer is option (C)