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Electric fields question

Hey,
I was ill when we had class on this so I have been left a bit stuck on this question.

Calculate the electrical potential and the electric field strength at position Z due to two charges X and Y placed in air as shown in diagram.

electricfields.jpg

5.0m = XZ = ZY = XY

Any help is appreciated!
Original post by RHCPfan
Hey,
I was ill when we had class on this so I have been left a bit stuck on this question.

Calculate the electrical potential and the electric field strength at position Z due to two charges X and Y placed in air as shown in diagram.

electricfields.jpg

5.0m = XZ = ZY = XY

Any help is appreciated!


So that we don't waste time helping you with what you already know, can you tell us what you know.
What equations do you know for the electric potential and electric field strength at a point a distance r from a charge Q?

The value at the point Z is the sum of the two due to the two individual charges.
The potential is just the straight sum, and the field strength has to be added as vectors.
Reply 2
Original post by Stonebridge
So that we don't waste time helping you with what you already know, can you tell us what you know.
What equations do you know for the electric potential and electric field strength at a point a distance r from a charge Q?

The value at the point Z is the sum of the two due to the two individual charges.
The potential is just the straight sum, and the field strength has to be added as vectors.


Like I said I missed out on the teaching of all this but from what I gather electrical field strength is E = F/Q and electrical potential is E = q x Ve.

Ok having tried to find more notes online for this I now have for electric field strength

E = 1/4piE0 x Q/r^2

For XZ - E = +10muC/5.0 m x 8.854 x 10^-12

For YZ - E = -10muC/5.0 m x 8.854 x 10^-12

Eo is a constant given at 8.854 x 10^-12

Is this going in the right direction?
(edited 9 years ago)
Original post by RHCPfan


Ok having tried to find more notes online for this I now have for electric field strength

E = 1/4piE0 x Q/r^2

For XZ - E = +10muC/5.0 m x 8.854 x 10^-12

For YZ - E = -10muC/5.0 m x 8.854 x 10^-12

Eo is a constant given at 8.854 x 10^-12

Is this going in the right direction?


Yes.

That's the equation for electric field strength.
This represents a force and is a vector.

The equation for electric potential is almost the same but has r and not r2
Potential is scalar and easier to add.
I suggest you start with the potential question.
Find the potential at that point due to each charge, using the formula, and add the values, taking account of whether the value is positive or negative. (due to the sign of the charge.)
Do you have the correct answer to check it?

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