Question
Some help on this question would be great!
A spherical capacitor is formed from two concentric spherical conducting shells separated by vacuum. The inner sphere has a radius of Ta = 12.4cm, and the outer sphere has a radius of Tb = 14.8cm . A potential difference of 120V is applied to the capacitor. What is the capacitor of the capacitor? Use epsilon 0 = 8.85 times 10 -12F/m for the permittivity of the free space. What is the magnitude E1 of the electric field at radius r = 12.8cm, just outside the inner sphere? What is the magnitude of at r = 14.6 cm, just inside the outer sphere?
Explanation / Answer
a)
C=4pieo/[(1/ra)-(1/rb)]
C=4pi*8.85*10^-12[(1/0.124)-(1/0.148)]
C=8.5*10^-11 F
b)
Q=CV =8.5*10^-11*120 =1.02*10^-8 C
E=KQ/r^2 =(9*10^9)(1.02*10^-8)/0.124^2
E=5973.2 V/m
C)
E=(9*10^9)(1.02*10^-8)/0.146^2
E=4306.62 V/m