A resistor develops 200 J of thermal energy in 5 s when a current of 2 A is passed through it. If the current is measured to 5 A, what will be the energy developed in 12 s?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) - 3000 J
$H=I^2Rt$ [Joules law of heating]
where,
H = thermal energy produced
I = current
R = Resistance
t = time
$200=(2)^2R(5)$
$R=\frac{200}{20}=10Ω$
∴ New energy, $H=(5)^2(10)(12)$
$=3000J$