- #1
jaus tail
- 615
- 48
Homework Statement
Homework Equations
V = L di/dt
Energy = V*I*t
The Attempt at a Solution
First we find out V across L
This V will be there only for 1st 2 seconds as after that there is no change in current.
So V(across L) is L * di/dt = 2 * 6/2 = 6V equation 1
Now Current is a function of time so it's i = 3t equation 2
So to get Energy we use integration.
Energy = integration of V*I*dt where limits are 0 to 2
So now using equation 1 and 2 we get
Energy = integration of 6 * 3t dt from limits 0 to 2
so this is 18 t2/2 t varies from 0 to 2
So this is 9 (4) = 36 which is not in the options.
Where am I wrong.
I even tried other formula of Energy = 1/2 * L * I2 But this gives 24
I'm getting different answer for different formula but neither answer matches options. Where am I wrong?