Hi there,(adsbygoogle = window.adsbygoogle || []).push({});

im having trouble finding the right equation for a problem ive got.

I have a point charge with an equipotential of 40v at 0.4cm. I am suppossed to work out the value of the charge.

Ive tried

q/4[tex]\pi[/tex][tex]\epsilon[/tex]r

but it doesnt work and i think its because im not putting in a value for [tex]\epsilon[/tex]

as i dont know what it is.

cols anyone tell me if a, im using the right equation and b, hot to find or put in the value of [tex]\epsilon[/tex]

many thanks

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# Homework Help: Equipotentials around a charge Q

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