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i have 2 questions for electromagnitism and i just cant do them. my lecturer is just not up to the job of teaching and everyone is struggling and its probably something easy. anyway rant over.

1) you have an equlateral trinagle with chare q in 2 corners. what charge would you have to put into the third corner so the centre has

a)0 electric field

b)0 electric potential

in part a) what is the electric potential

in part b) what is the electic field

for this i have just been plating with trigonomatry and it just seems to longwinded for an answer that just doesnt seem right.

2) state how electric field can be calculated by electric potential.

the electric potential at derpendicular distance r from a long straight wire with cross section a is

v(r)=-k ln (r/a)

k is constant. calculate electric field as a function of r.

i know this is to do with intergrating or differentiating but not sure which.

if someone would be so kind to answer these and also give some details on elecromagnitism as a whole that would be amazing.

THANKS ALL

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# Homework Help: What is the electric potential

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