An inductor of 2.00 H is connected to a battery. There is nevertheless resistanc
ID: 3896066 • Letter: A
Question
An inductor of 2.00H is connected to a battery. There is nevertheless resistance in the circuit, in both the inductor and the battery. Assume that its value is 8.10? and it behaves just like a simple resistor in series with a pure inductor and an ideal battery of emf 6.40V .
Part A:Consider the instant one time constant after the inductor is connected to the battery. Calculate the energy that resides in the inductor's magnetic field at this instant.
Answer: .249J
Part B:How much energy was supplied by the (ideal) battery from the time it was first connected to the inductor to the instant one time constant later?
Explanation / Answer
time constant=L/R=0.247 sec
in 1 time constant,
current=(6.4/8.1)*(1-exp(-1))=0.5 A
so energy=0.5*L*current^2=0.249 J
part B:
energy supplied=integral of 6.4*current*dt
with t=0 to t=0.247
answer=0.4594 J
part C:
0.4594-0.249=0.2104 J