A Flat Rectangular Loop of Wire Is Placed Between the Poles

question 80

Multiple Choice

A flat rectangular loop of wire is placed between the poles of a magnet, as shown in the figure. It has dimensions w = 0.60 m and L = 1.0 m, and carries a current I = 2.0 A in the direction shown. The magnetic field due to the magnet is uniform and of magnitude 0.80 T. The loop rotates in the magnetic field and at one point the plane of the loop makes a 30° angle with the field. At that instant, what is the magnitude of the torque acting on the wire due to the magnetic field?

• A) 0.30 N ∙ m
• B) 0.40 N ∙ m
• C) 0.48 N ∙ m
• D) 0.83 N ∙ m
• E) 0.96 N ∙ m

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Definitions:

Voluntary Fixation

A consciously controlled process of stabilizing focus on a particular stationary or moving object.

EOG

Electrooculography, a technique for measuring the corneo-retinal standing potential that exists between the front and the back of the human eye.

Snellen Eye Chart

A chart used to measure visual acuity, consisting of rows of letters decreasing in size, which is read from a standard distance.

Ophthalmoscope

A medical device used by doctors to examine the inside of the eye, including the retina and the optic nerve.