A107-turn circular coil of radius 2.41 cm is immersed in a uniform magnetic field that is perpendicular to the plane of the coil. during 0.115 s the magnetic field strength increases from 52.1 mt to 91.7 mt. find the magnitude of the average emf, in millivolts, that is induced in the coil during this time interval.

Average emf in the coil: 0.0672 V.

Explanation:

Convert all units to standard SI units.

Consider Faraday's Law of Induction:

where

The coil is circular with a radius of . As a result,

.

Neither nor changes in this 0.115 seconds. As a result, the average rate of change in is the same as times the average rate of change in .

.

All numbers in the question come with three sig. fig. Keep more sig. fig. than that in the calculation but round the final answer to three sig. fig.

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