Question

The north pole of a magnet is brought down along the axis of a horizontal circular coil (see the following figure). As a result, the flux through the coil changes from 0.35 weber to 0.85 weber in an interval of half a second. Find the average emf induced during this period. Is the induced current clockwise or anticlockwise as you look into the coil from the side of the magnet ?

Answer 1

Given:-

Initial flux, ϕ₁ = 0.35 weber

Final flux ϕ₂ = 0.85 weber

∴ Δϕ = ϕ₂ − ϕ₁

= (0.85 − 0.35) weber

= 0.5 weber

Also,

Δt = 0.5 s

The magnitude of the induced emf is given by

\[e = \frac{∆ \phi}{∆ t} = \frac{0 . 5}{0 . 5} = 1  V\]

The induced current is anti-clockwise when seen from the side of the magnet.