Answer:
10.2 Watt
Explanation:
[tex]N[/tex] = number of turns in flat coil = 160
[tex]A[/tex] = area = 0.20 m²
B₀= initial magnetic field = 0.40 T
[tex]B[/tex] = final magnetic field = - 0.40 T
Change in magnetic field is given as
ΔB = B - B₀ = - 0.40 - 0.40 = - 0.80 T
[tex]t[/tex] = time taken for the magnetic field to change = 2.0 s
Induced emf is given as
[tex]E = \frac{- N A \Delta B}{t}[/tex]
[tex]E = \frac{- (160) (0.20) (- 0.80)}{2}[/tex]
[tex]E[/tex] = 12.8 volts
[tex]R[/tex] = Resistance of the coil = 16 Ω
Power is given as
[tex]P = \frac{E^{2}}{R}[/tex]
[tex]P = \frac{(12.8)^{2}}{16}[/tex]
[tex]P[/tex] = 10.2 Watt