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

Answer:

Current through circuit will be $0.2706\times 10^6A$

Explanation:

We have given source voltage v = 50 volt

Resistance $R=25Mohm=25\times 10^6ohm$

Capacitance $C=0.1\mu F=0.1\times 10^{-6}F$

Time t = 5 sec

Time constant of RC circuit is given by $\tau =RC=25\times 10^6\times 0.1\times 10^{-6}=2.5sec$

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

$v_c=50(1-e^{\frac{-5}{2.5 }})=43.2332v$

So current will be $=\frac{v_s-v_c}{R}=\frac{50-43.2332}{25\times 10^{-6}}=0.2706\times 10^6A$

So current through circuit will be $0.2706\times 10^6A$