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A parallel-plate capacitor with plate area 2.6 cm^2 and air-gap separation 0.25 mm is connected to a 30 V battery, and fully charged. The battery is then disconnected.


I Solved most of the parts of this q's but not this one:


The plates are now pulled to a separation of 0.55 mm. What is the charge on the capacitor now?


note:

I found 125.5pC and the answer unit is pC

Respuesta :

Answer:

276.12 pC

Explanation:

We are given that

Area,A=[tex]2.6 cm^2=2.6\times 10^{-4}m^2[/tex]

Where [tex]1 cm^2=10^{-4} m^2[/tex]

[tex]d=0.25 mm=0.25\times 10^{-3} m[/tex]

[tex]1mm=10^{-3} m[/tex]

Potential difference, V=30  V

We have to find the charge on the capacitor when the plates are pulled to a separation of 0.55 mm.

We know that

Charge ,[tex]Q=\frac{\epsilon_0 A V}{d}[/tex]

Where [tex]\epsilon_0=8.85\times 10^{-12}[/tex]

Using the formula

[tex]Q=\frac{8.85\times 10^{-12}\times 2.6\times 10^{-4}\times 30}{0.25\times 10^{-3}}[/tex]

[tex]Q=2.7612\times 10^{-10} C[/tex]

[tex]Q=276.12p C[/tex]

[tex]1 pC=10^{-12} C[/tex]

When the plates are now pulled to a separation of 0.55 mm.Then, the charge on the plates remain same because the  battery has been disconnected.

Therefore, charge on the capacitor=276.12 pC