Question

A parallel plate capacitor (of capacitance \( C \)) with circular plates of radius \( r_0 \) located at positions \( \pm \alpha \), is connected in series with a resistor \( R \) and is charged by a battery of voltage \( V \). Consider a circular loop \( L \) of radius \( \frac{r_0}{2} \) parallel to the capacitor plates is located at the center. Which of the following statements is correct?

• A. The charge on the capacitor at time $t$ is $q(t) = CR(1-e^{-t/(CV)})$
• B. The charge on the capacitor at time $t$ is $q(t) = CV(1-e^{-t/(CV)})$
• C. The flux through the loop L is independent of the area enclosed by it
• D. The magnetic field is directed orthogonal to the loop L
• E. The magnetic field is directed along the loop L

Hint:

In charging circuits, always check the exponent. It must have the dimensions of time ($RC$). If you see $CV$ in the exponent, it is a dimensional error.

Answer 1

The Correct Option is B