Correct Answer - Option 1 : 0.02

**Concept:**

The average value of the induced emf across the coil is

\(E = N\frac{{dϕ }}{{dt}}\) ...(1)

Where,

E = Induced emf in volt

N = number of turns of the coil

ϕ = Total flux in webers

**Calculation:**

Given,

E = 40 V, t = 0.5 s, N = 1000

From equation (1),

\({40 = 1000 \times \frac{{dϕ }}{0.5}}\)

\(dϕ = \frac{{40 \times 0.5}}{{1000}}\)

dϕ = 0.02 weber

Flux linkage = **0.02 wb**