How Do You Calculate the Leakage Resistance of a Capacitor?

[tommoturbo]

1. Calculate the leakage resistance across a capacitor of 100pF that has a relative permittivity of 12 and a resistivitty of rho=10*14



2. Rl=rho x Er x Eo /C
Rl=^10*14 x ^{12 x 8.85*-12} / ^100*-12



3. ^Rl=1.062*15


surley the leakage resistance can't be that high my friend said it should be this formula

You need to use the formula; R = rho E/C (it's the lesson books somewhere!), where E = ErEo.

So, E = ErEo which is; 12*8.85*10^-12. This equals 1.062*10^-10

Therefore R = 1014 * 1.062*10^-10/100*10^-12.

This gives R as 1076.87 ohms.

 

[overt26]

I calculated

$$R_{leak}=1.062\times10^{14}$$ ohms

Sure it's a big value - not something you measure with a multimeter! - but an ideal capacitor would have infinite leakage resistance.

 

[Mene]

Thank you for your input. I agree that the leakage resistance cannot be as high as calculated in the first formula. The second formula provided, R = rho E/C, is the more accurate formula to use in this situation. Using this formula, the calculated leakage resistance is 1076.87 ohms, which is a more reasonable value. It is important to always double check formulas and units to ensure accurate calculations in scientific work.