For a single loop

PHYSICS · Single correct · A Level · Physics · Fields and their consequences · Fields and their consequences

Problem

For a single loop, the magnetic field is

0.25\,\text T

, the area is

0.15\,\text{m}^2

, and the angle between the field and the normal to the loop is

60^{\circ}

. At this moment, the field is increasing at

0.040\,\text T\,\text s^{-1}

and the angle is decreasing at

2.0\,\text{rad}\,\text s^{-1}

. Determine the rate of change of area that will keep the induced emf zero at this instant. (a)

+0.25\,\text{m}^2\,\text s^{-1}

(b)

+0.50\,\text{m}^2\,\text s^{-1}

(c)

-0.50\,\text{m}^2\,\text s^{-1}

(d)

-0.25\,\text{m}^2\,\text s^{-1}