A capacitor is composed of 2 plates separated by a sheet of insulating material 2mm thick and of relative permittivity 3. The distance between the plates is increased to allow the insertion of a second sheet of 3mm thick and of relative permittivity Er If the equivalent capacitance is one-half of the original capacitance , find the value of Er: Ans: € 4.5
In the given network, each capacitor has € = 4.00 pF ad Vab +28.0 V.Calculate the:
a. Total capacitance Ans: CT 2. 4uF Charge on each capacitor Ans: Q1 Qz 22.4uC, Q3 = 44.8uC,Q4 = 67.2uC c. Potential difference on each capacitor Ans: Vi Vz 5.6V, Vz 11.2V,V4 16.8V
A 20 AF capacitor is charged to 120 V and then disconnected from the power supply: If a second uncharged capacitor with capacitance of 50 uF is connected across the first capacitor; what would be the resulting voltage across their parallel combination? Ans: Vr = 34.286V A parallel-plate capacitor in air has a plate separation of 1.35 cm and a plate area of 35.0 cm?. The plates are charged to a potential difference of 150 V and disconnected from the source. The capacitor is then immersed in distilled water. Assume the liquid is an insulator. Determine: the charge on the plates before and after immersion Ans: Q = 344.33 pC b: the capacitance and potential difference after immersion Ans: € = 183.65pF,V = 1.875V the change in energy of the capacitor after immersion Ans: AU -25.Sn)
Find the relative permittivity er of the dielectric material present in a parallel-plate capacitor if: A=0.12 m2,d= 80 um; V=12V,U=1 pJ Ans: & 1.046