Question

In the connection shown in the figure the switch K is open and the capacitor is uncharged. Then we close the switch and let the capacitor charge up to the maximum and open the switch again. Then (Use the following data : $V_0=30V,R_1=10k\Omega ,R_2=5k\Omega )$

• A. the current through R1 immediately after closing the switch is 3 mA
• B. the current through R2 immediately after the switch was closed in 2 mA
  
• C. the current through R2 immediately after reopening the switch 2 mA
  
• D. the current through R1 immediately after reopening the switch is zero

Answer 1

Answer: (A), (C), (D)

The correct options are
A

the current through R1 immediately after closing the switch is 3 mA

C

the current through R2 immediately after reopening the switch 2 mA

D

the current through R1 immediately after reopening the switch is zero

Just after closing switch no current flows through $R_2$ sol $I_1=3mA$
Long time after closing switch no current flows through C so $I_2=2mA$
Directly after re-opening the switch no current flows through R1 and the capacitor will discharge thorough $R_2$ so $I_3=2mA$.