Capacitance and maximum charge HELP

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SUMMARY

The discussion centers on calculating the capacitance of a parallel-plate capacitor modeled by a cloud and the ground, with the cloud at an altitude of 620 meters and a surface area of 0.40 km². The formula used is C = E0 * A / D, where E0 is the permittivity of free space (8.85 x 10^-12 C²/N·m²), A is the area of the plates, and D is the distance between them. Participants seek assistance in determining the capacitance in nanofarads (nF) and the maximum charge the cloud can hold before lightning occurs.

PREREQUISITES
  • Understanding of parallel-plate capacitor theory
  • Familiarity with the formula C = E0 * A / D
  • Knowledge of dielectric strength of air
  • Basic unit conversions (km² to m², etc.)
NEXT STEPS
  • Calculate capacitance using the provided formula and parameters
  • Research dielectric strength of air to determine maximum charge
  • Explore the implications of capacitance in atmospheric electricity
  • Investigate real-world applications of capacitors in meteorology
USEFUL FOR

Students and professionals in physics, electrical engineering, and meteorology who are interested in understanding the principles of capacitance and its application in atmospheric phenomena like lightning.

seant
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As a crude model for lightning, consider the ground to be one plate of a parallel-plate capacitor and a cloud at an altitude of 620 m to be the other plate. Assume the surface area of the cloud to be the same as the area of a square that is 0.40 km on a side.
(a) What is the capacitance of this capacitor?
nF
(b) How much charge can the cloud hold before the dielectric strength of the air is exceeded and a spark (lightning) results?
C

I used C=E0 A/D (8.85*10^-12 C^2/N*m^2)(.16km^2/620m) and conversions also, but to no avail can someone please help
 
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Hi seant,

seant said:
As a crude model for lightning, consider the ground to be one plate of a parallel-plate capacitor and a cloud at an altitude of 620 m to be the other plate. Assume the surface area of the cloud to be the same as the area of a square that is 0.40 km on a side.
(a) What is the capacitance of this capacitor?
nF
(b) How much charge can the cloud hold before the dielectric strength of the air is exceeded and a spark (lightning) results?
C

I used C=E0 A/D (8.85*10^-12 C^2/N*m^2)(.16km^2/620m) and conversions also, but to no avail can someone please help

What number did you get as your final answer, in nF?
 

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