2. A parallel-plate capacitor has an area of 2.0 cm², and the plates are separated by 2.0 mm. a. What is the capacitance? b. How much charge does this capacitor store when connected to a 6.0 V battery?

Respuesta :

Given data:

* The area of the parallel plate capacitor is,

[tex]\begin{gathered} A=2cm^2 \\ A=2\times10^{-4}m^2^{} \end{gathered}[/tex]

* The distance between the plates is,

[tex]\begin{gathered} d=2\text{ mm} \\ d=2\times10^{-3}\text{ m} \end{gathered}[/tex]

Solution:

(a). The capacitance of the capacitor in terms of area and distance between the plates is,

[tex]C=\frac{\epsilon_{\circ}A}{d}[/tex][tex]\text{where }\epsilon_{\circ}\text{ is the electrical permittivity of the fr}ee\text{ spaces}[/tex]

Substituting the known values,

[tex]\begin{gathered} C=8.85\times10^{-12}\times\frac{2\times10^{-4}}{2\times10^{-3}} \\ C=8.85\times10^{-13}\text{ F} \end{gathered}[/tex]

Thus, the value of the capacitanc is 8.85 times 10 power -13 Farad.

(b). The voltage across the battery is,

[tex]V=6\text{ Volts}[/tex]

The charge stored in the capacitor in terms of the voltage and the capacitance is,

[tex]\begin{gathered} C=\frac{Q}{V} \\ Q=CV \end{gathered}[/tex]

where Q is the charge stored in the capacitor

Substituting the known values,

[tex]\begin{gathered} Q=8.85\times10^{-13}\times6 \\ Q=53.1\times10^{-13}\text{ Coulomb} \end{gathered}[/tex]

Thus, the charge stored in the parallel plate capacitor is 53.1 times 10 power -13 coulomb.