Two identical air-filled parallel-plate capacitors C1 and C2 are connected in series to a battery that has voltage V. The charge on each capacitor is Q0. While the two capacitors remain connected to the battery, a dielectric with dielectric constant K>1 is inserted between the plates of capacitor C1, completely filling the space between them.

What is the total positive charge stored on the two capacitors?
Express your answer with the appropriate units.

Respuesta :

Answer:

Explanation:

In the first case,

Q₀ = C₁ V, where C₁ is equivalent capacitance of two capacitor having capacitance C  each.

C₁ = C / 2

Q₀ = CV / 2

CV = 2Q₀

Total charge = 2Q₀ = CV

In the second case ,

capacitance will be kC and C .

equivalent capacitance

C₂ = kC x C / ( kC + C)

= kC / ( 1+k)

Charge on each capacitor = V x C₂

= kCV / ( 1+k)

=  2kQ₀ / ( 1+k)

This will be the charge on each capacitor. So

total charge = 4kQ₀ / ( 1+k)

The total positive charge stored on the two capacitors is;

4kQ₀/(k + 1)

We are told that the charge on each capacitor is Q₀.

Now, formula for charge stored on a capacitor is;

Q = CV

Where;

Q is charge

C is capacitance

V is voltage

Thus, total charge stored on the two capacitors will be;

Q = Q₁ + Q₂

Since Q₀ is the charge on each capacitor, then;

For Capacitor 1, we have; Q₀ = C₁V

For capacitor 2, we have; Q₀ = C₂V

Thus, let the capacitance C₁ be be half the capacitance C of two capacitors.

Thus;

C₁ = ¹/₂C

Thus;

Q₀ =  ¹/₂CV

2Q₀ = CV

Now, a dielectric with dielectric constant k > 1 is inserted between the plates of capacitor C₁. Thus, the two capacitors will now be kC and C.

Thus;

C₂ = (kC × C)/(kC + C)

C will cancel out to give;

C₂ = kC/(k + 1)

Earlier on, we saw that;

Q₀ = C₂V

Thus;

Q₀ = kCV/(k + 1)

Earlier, we saw that 2Q₀ = CV

Thus, charge is;

Q₀ = 2kQ₀/(k + 1)

Since 2 capacitors, then total positive charge stored is;

2 × 2kQ₀/(k + 1) = 4kQ₀/(k + 1)

Read more at; https://brainly.com/question/15053223

ACCESS MORE