Answer:
Step-by-step explanation:
Given that,
Number of turns is 119
N = 119
The radius of the coils is 2.47 cm
R = 2.47 cm = 0.0247m
Then, the area of the circular coil is given as
A = πr²
A = π × 0.0247²
A = 1.917 × 10^-3 m²
Time interval
t = 0.167s
The magnetic field strength increases from B1 = 57.9mT to B2 = 96.9 mT
Then,
∆B = B2 - B1 = 96.9 — 57.9 = 39 mT
∆B = 39 × 10^-3 T
We want find the average emf
EMF induced in a coil is given as
ε = -N dΦ / dt
Then, magnetic flux (Φ) is given as
Φ = BA
Then,
ε = -N dΦ / dt
ε = -N d(BA) / dt
Since the area is constant, so we have
ε = -N•A dB / dt
ε = -N •A • ∆B / ∆t
So, inserting the parameters above
ε = - 199 × 1.917 × 10^-3 × 39 × 10^-3 / 0.167
ε = 0.0891 V
To mV
ε = 89.1 × 10^-3 V
ε = -89.1 mV
Then, the magnitude of EMF induced in the coil is 89.1 mV