Question

A 50-V de voltage source was connected in series with a resistor and capacitor. Calculate the current in A to two significant figures) after 5.0 s if the resistance was 25 MΩ and the capacitance 0.10μF.

Answer 1

Current through circuit will be
`0.2706* 10^6A`

Step-by-step explanation:

We have given source voltage v = 50 volt

Resistance
`R=25Mohm=25* 10^6ohm`

Capacitance
`C=0.1\mu F=0.1* 10^(-6)F`

Time t = 5 sec

Time constant of RC circuit is given by
`\tau =RC=25* 10^6* 0.1* 10^(-6)=2.5sec`

We know that voltage across capacitor is given by
`v_c=v_s(1-e^{(-t)/(\tau )})`

`v_c=50(1-e^{(-5)/(2.5 )})=43.2332v`

So current will be
`=(v_s-v_c)/(R)=(50-43.2332)/(25* 10^(-6))=0.2706* 10^6A`

So current through circuit will be
`0.2706* 10^6A`