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CUET · PHYSICS · PYQ PAPER 2025

A current through a wire varies with time, as \( I = \alpha t + \beta t^2 \) where \( \alpha = 10 \, \text{A s}^{-1} \) and \( \beta = 4 \, \text{A s}^{-2} \). How much charge will cross through a section of the wire in 12 s?

  1. A 106 C
  2. B 696 C
  3. C 912 C
  4. D 3024 C
Verified Solution

Answer & Solution

Correct Answer

(D) 3024 C

Step-by-step Solution

Detailed explanation

\( Q = \int_{0}^{12} (\alpha t + \beta t^2) \, dt \) \( Q = \left[ \frac{\alpha t^2}{2} + \frac{\beta t^3}{3} \right]_{0}^{12} = \frac{10(12)^2}{2} + \frac{4(12)^3}{3} \) \( Q = 720 + 2304 = 3024 \, \text{C} \)