Maximum Voltage without causing Dielectric Breakdown?

[mli273]

1. What plate area is required if an air-filled, parallel-plate capacitor with a plate separation of 2.3 mm is to have a capacitance of 24 pF?

Which I found correctly to be 6.2 x 10^-3 m^2 by using the formula C= k(8.85x10^-12)A/d

What is the maximum voltage that can be applied to this capacitor without causing dielectric breakdown?


2. I know V=Q/C, and that I have C, but I'm not sure what to substitute for Q, or if I need another formula completely. Help?

 

[Dickfore]

You should know the value for the critical electric field E_c in air (the electric field that would cause electric breakdown) and calculate the voltage from the formula:

$$E = V/d$$

 

[mli273]

3x10^6= V/.0023, so V = 6900 Volts. Thank you, I always have trouble on the simple ones.

 

[Dickfore]

You have too many significant figures in your end result, by the way. Because you stated the value of the critical field with one significant figure only, it means you should state your maximum voltage with that many significant figures. This should lead to a value of 7 kV.

 

[rwisz]

I would like to clarify that the maximum voltage that can be applied to a capacitor without causing dielectric breakdown is dependent on the dielectric strength of the material used as the dielectric between the plates. The dielectric strength is the maximum electric field that a material can withstand before undergoing dielectric breakdown. This value varies for different materials and can be found in tables or experimentally determined.

To calculate the maximum voltage, you can use the formula V = Ed, where E is the electric field strength and d is the distance between the plates. Since the electric field strength is equal to the voltage divided by the distance, we can rearrange the formula to E = V/d.

Therefore, to determine the maximum voltage, we need to know the dielectric strength of the material and the plate separation distance. Once we have these values, we can calculate the maximum voltage using the formula V = Ed.

I would also like to mention that it is important to choose a material with a high dielectric strength to ensure that the capacitor can withstand high voltages without undergoing dielectric breakdown. Additionally, proper insulation and safety measures should be taken when working with high voltages to avoid any accidents.

In conclusion, the maximum voltage that can be applied to a capacitor without causing dielectric breakdown is dependent on the dielectric strength of the material and can be calculated using the formula V = Ed. It is important to choose a material with a high dielectric strength and take necessary precautions when working with high voltages.