Figure 3.188 shows two parallel and coaxial loops. The smaller loop (radius r) is above the larger loop (radius R), by distance `x gtgt R`. The magnetic field due to current `i` in the larger loop is nearly constant throughout the smaller loop. Suppose that `x` is increasing at a constant rate of `dx//dt = v`.

The induced emf in the smaller loop is

Explanation

(a)`μ_(0)iR^(2)pir^(2)//2x^(3)`, (b) `3μ_(0)ipiR^(2)r^(2)v//2x^(4)`, (c) counterclockwise