Answer:
250 loops
Explanation:
We know that induced emf, E = -NdФ/dt wnere N = number of turns and dФ/dt = rate of change of magnetic flux.
Let E₁, E₂ and N₁, N₂ be the emfs and number of turns of coils 1 and 2 respectively. Since dФ/dt is the same for both coils,
E₁ = -N₁dФ/dt (1) and E₂ = -N₂dФ/dt (2)
Dividing (1) by (2), we have
E₁/E₂ = -N₁dФ/dt/-N₂dФ/dt = N₁/N₂
E₁/E₂ = N₁/N₂
N₂ = (E₂/E₁)N₁
Given that E = 2.78 V, N₁ = 159 loops and E₂ = 4.11 V,
N₂ = (E₂/E₁)N₁ = (4.11/2.78)159 = 250 loops