# magnets

posted by
**BJ**
.

A very large loop of metal wire with radius 1 meter is driven with a linearly increasing current at a rate of 200 amps/second. A very small metal wire loop with radius 5 centimeter is positioned a small distance away with its center on the same axis (the loops are coaxial). The small loop experiences an induced emf of 983 nano-volts. What is the separation of the loops in meters? Note that a subtraction step in the solution makes it sensitive to significant figures. Keep at least four figures in your calculation.