Answer:
i = 101.4A
Explanation:
The steps to the solution can be found in the attachment below.
We have been given the frequency f = 60Hz. From this we can calculate the angular frequency of the power line.
It is assumed that sinwt = –1 in order to calculate the time varying current. Although the magnitude of the current is large, consideration should also be given to the distance between the coil and the power line. The induced emf is small considering the area of the coil which is 7.85×10-⁵m².
Answer: a) 0.13*τ ; b) 2.08*τ
Explanation: In order to explain the discharg of a capacitor through a resistor, we have to consider the following:
Q(t)=Qo* exp(-t/τ) for a lose of 1/8-th of its charge
in this case, Q(t)=7/8*Qo=7/8*exp(-t/τ)
ln(7/8)*τ=-t
then, t= -ln(7/8)*τ =0.13
For a lose of 7/8 th of its charge , we have
Q(t)=1/7*Qo*exp(-t/τ)
t=-ln(1/8)*τ=2.08