For the circuit shown in the figure below, C = 6.5 mu F, = 100 V, and R = 490 Oh
ID: 1599048 • Letter: F
Question
For the circuit shown in the figure below, C = 6.5 mu F, = 100 V, and R = 490 Ohm. After having been at contact a for a long time, the switch throw is rotated to contact b. 1) What is the charge on the upper plate of the capacitor just as the switch throw is moved to contact b? 2) What is the current just after the switch throw is rotated to contact b? 3) What is the time constant of this circuit? 4) How much charge is on the upper plate of the capacitor 5.4 ms after the switch throw is rotated to contact b?Explanation / Answer
1.the maximum charge stored is
Q=6.5*10pow-6*100c
=650,micro coulomb
2.the current value is
I=q0/RC
,=0.204A
3.time constant=resistance*capacitance
=490*6.5*10-6
=3185 micro seconds
4. Current after some time
I=(qo/RC)epow -(t/RC)
Substituting the values we can calculate current value