In an R-C circuit while charging, the graph of lnI versus time is as shown by the dotted line in the adjoining diagram where I is the current. When the value of the resistance is doubled, which of the solid curves best represents the variation of ln I versus time? [image:7_image8.png]

Question

Dr. Abubacker · Accepted Answer

(b) Charging current, $I = \frac{E}{R}\ e^{- \frac{t}{RC}}$
Taking log both sides,
$\ {Log}{I = \log{\left( \frac{E}{R} \right) - \frac{t}{RC}}}$
When R is doubled, slope of curve increases. Also at t = 0, the current will be less. Graph Q represents the best.

Q. In an R-C circuit while charging, the graph of lnI versus time is as shown by the dotted line in the adjoining diagram where I is the current. When the value of the resistance is doubled, which of the solid curves best represents the variation of ln I versus time?

Explanation

Reviewed by Dr. Abubacker

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