A capacitor of capacity `C` is charged to a steady potential difference `V` and connected in series with an opne key and a pure resistor 'R'. At time `t = 0`, the key si closed. If `I =` current at time `t`, a plot of `log I` against 't' is as shown in `(1)` in the graph. Later one of the parametrs i.e. `V,R` or `C` is charged keeping the other two constant, and graph `(2)` is recored. then-

Options

A. `V_(0)` is decreased
B. R is decreased
C. R is increased
D. C is decreased

Answer

D

Explanation

`I=(V_(0))/(R)e^(-t//RC)`
`l nI=l n(V_(0))/(R)(t)/(RC)`
In both cases log of initial current is same that means `(V_(0))/(R)` is constant to keep `(V_(0))/(R)` constant both `V_(0))` and R have to be changed whereas it is stated that only one parameter out of `V_(0),R` and C is changed Therefore only C has been changed and to match the straight line the graph, it is decreased.