If an uncharged capacitor is connected to a battery, one capacitor plate becomes
ID: 2280479 • Letter: I
Question
If an uncharged capacitor is connected to a battery, one capacitor plate becomes negatively charged as electrons move from the interior of the plate to the plate face. In the figure the depth d from which the electrons come in the plate in a particular capacitor is plotted against a range of values for the potential difference V of the battery. The vertical scale is set by ds = 4.00 pm, and the horizontal scale is set by Vs = 30.0 V. Assume the plate is made of copper with a density of conduction electrons of 8.49
If an uncharged capacitor is connected to a battery, one capacitor plate becomes negatively charged as electrons move from the interior of the plate to the plate face. In the figure the depth d from which the electrons come in the plate in a particular capacitor is plotted against a range of values for the potential difference V of the battery. The vertical scale is set by ds = 4.00 pm, and the horizontal scale is set by Vs = 30.0 V. Assume the plate is made of copper with a density of conduction electrons of 8.49 times 1028 electrons/m3. What is the ratio C/A?
Explanation / Answer
Q=CV
and
Q=(nAd)*e
CV =nAde
C/A =nde/V =(8.49*10^28)*(4*10^-12)*(1.6*10^-19)/30
C/A=1.81*10^-3 F/m^2 or 1.81 mF/m^2