A current of strength $I = 2$ A flows for a time $t = 10$ s through a conductor of resistance $R = 5$ ohm. Find the quantity of heat released in the conductor.
Joule-Lenz law: $Q = I^2 R t$.
$$Q = 2^2 \cdot 5 \cdot 10 = 4 \cdot 5 \cdot 10 = 200 \text{ J}$$
$Q = 200$ J