Q 12-03-089JEE MainJEE Main 2024 (29 Jan, Shift 1)Easy
The electric current through a wire varies with time as $I = I_0 + \beta t$, where $I_0 = 20\ \text{A}$ and $\beta = 3\ \text{A s}^{-1}$. The amount of electric charge crossed through a section of the wire in $20\ \text{s}$ is:
Answer: (B) $1000\ \text{C}$
$$q = \int_0^{20}(20 + 3t)\,dt = 20\times20 + \frac32(20)^2 = 400 + 600 = 1000\ \text{C}$$
Solution by Sreeraj P, M.Sc Physics