An initially uncharged air-filled capacitor is connected to a 5.67-V charging so
ID: 1590719 • Letter: A
Question
An initially uncharged air-filled capacitor is connected to a 5.67-V charging source. As a result, 3.49 × 10-5 C of charge is transfered from one of the capacitor's plates to the other. Then, while the capacitor remains connected to the charging source, a sheet of dielectric material is inserted between its plates, completely filling the space. The dielectric constant of this substance is 5.99. Find the capacitor's potential difference and charge after the insertion.
Please show all work! Thank you!
Explanation / Answer
V = potential difference = 5.67 volts
Qo = charge stored by the capacitor when without dielectric = 3.49 x 10-5 C
Co = Capacitance of capacitor without the dielectric
Using the formula
Qo = Co V
(3.49 x 10-5 ) = Co (5.67)
Co = 6.2 x 10-6 F
k = dielectric constant = 5.99
C = Capacitance with the dielectric = k Co = 5.99 (6.2 x 10-6 ) = 37.14 x 10-6 F
Potential difference is due to the external charging source so it remains same
V = potential difference after insertion = 5.67 volts
New charge stored , Q = C V = (37.14 x 10-6 )(5.67) = 0.000211 C