Question:
A resistor develops $500 \mathrm{~J}$ of thermal energy in 20 s when a current of $1.5 \mathrm{~A}$ is passed through it. If the current is increased from $1.5 \mathrm{~A}$ to $3 \mathrm{~A}$, what will be the energy developed in $20 \mathrm{~s}$.
Correct Option: , 4
Solution:
(4)
$500=(1.5)^{2} \times \mathrm{R} \times 20$
$\mathrm{E}=(3)^{2} \times \mathrm{R} \times 20$
$\mathrm{E}=2000 \mathrm{~J}$