KVPY Sample Paper KVPY Stream-SX Model Paper-3

If at \[t=0\] the switch \[{{S}_{w}}\] is closed, then the charge on capacitor in the given circuit (initially uncharged) when the current through battery becomes 50% of its maximum value is (assume battery is ideal):

A) \[\frac{C\varepsilon }{3}\]

B) \[\frac{C\varepsilon }{2}\]

C) \[\frac{C\varepsilon }{4}\]

D) \[C\varepsilon \]

Correct Answer: D

Solution :

\[{{I}_{\max }}=\frac{2\varepsilon }{R}\] at \[t=0\]

\[I=\frac{\varepsilon }{R}\] at \[t=\infty \]

so charge on the capacitor is \[C\varepsilon ,\] when current is 50% of maximum current.