Question

When the key $K$ is pressed at time $t=0$, which of the following statements about the current $I$ in the resistor $A B$ of the given circuit is true?

• A. $I=2 \,mA$ at all $t$
• B. $I$ oscillates between $1\, mA$ and $2\, mA$
• C. $I=1 \, mA$ at all $t$
• D. At $t=0, I=2\, mA$ and with time it goes to $1 \, mA$

Answer 1

Answer: (D)

At time $t=0$ i.e., when capacitor is charging, current $i=\frac{2}{1000}=2\, mA$
When capacitor is fully charged, no current will pass through it.
Hence, current through the circuit is $i=\frac{2}{2000}=1\, mA$