The charge flowing in an electrical circuit is given by the equation \( Q=t^2-2t+4 \). The current in the circuit at \( t = 2 \) sec is:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 2 A
The current is the rate of flow of charge, \( I = \frac{dQ}{dt} \), so it is found by differentiating \( Q(t) \) and then putting in the time.
\( I = \frac{d}{dt}(t^{2}-2t+4) = 2t-2 \)
\( I\big|_{t=2} = 2\times2-2 = 2\,\mathrm{A} \)