The heat released in 20s is 5760J
Step-by-step explanation:
Given:
Time, t = 20s
Resistor, R₁ = 6Ω
R₂ = 3Ω
Voltage, V = 24V
Heat, H = ?
When the two resistors are connected in parallel, the net resistance would be:

Substituting the value in the above formula we get:


The net resistance is 2Ω
According to the joule's law:

On substituting the value we get:

Therefore, heat released in 20s is 5760J