Rankers Physics

Charging and Discharging of Capacitors: Practice Problem & Solution

When the key K is pressed at t = 0, which of the following statements about the current I in the resistor AB of the given circuit is true ? Charging and Discharging of Capacitors diagram: When the key K is pressed at t
I = 2 mA at all t
I oscillates between 1 mA and 2 mA
I = 1 ma at all t
at t = 0, I = 2mA and with time it goes to 1 mA

Solution Explained:

To solve this problem, we apply the core principles of Charging and Discharging of Capacitors. Understanding the underlying formula is key to arriving at the correct answer below:

At t =0 capacitor behaves as closed circuit to the 1000 ohm resistor connected in parallel with capacitor will get short circuited.

current  through the other resistor = 2/1000 = 2mA

At t = infinite capacitor behaves as open circuit so equivalent resistance becomes R=1000+1000 = 2000 Ohm

current  through the  resistor = 2/2000 = 1 mA

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