To calculate the total energy stored in the circuit, we need to use the formula for energy stored in an inductor, which is given by:

W = 0.5 L I^2

First, we need to find the total resistance in the circuit. Since the inductor and resistors are connected in series, the total resistance (R_total) can be calculated by adding the resistances of each component:

R_total = r + R1 + R2
R_total = 0.5 + 1.5 + 3.5
R_total = 5.5 Ohm

Next, we need to find the total current in the circuit. The total current (I) can be calculated using Ohm's Law:

E = I R_total
8 = I 5.5
I = 8 / 5.5
I = 1.4545 A

Now, we can calculate the total energy stored in the circuit using the formula:

W = 0.5 L I^2
W = 0.5 0.5 (1.4545)^2
W = 0.25 * 2.1120
W = 0.528 H

Therefore, the total energy stored in the circuit is 0.528 Joules.