Physics question?

Question

Four identical point charges, Q, are placed at the corners of a square. Each side of the square has length 2.0 m. Determine the magnitude of the electric field at the point P, the center of the square.

I really don't understand the question. I think its missing something. Could someone help me out.

Answer 1

The Electric field is given by the formula E=kQ/r². But it is a vector . That means that the electric fiel has a direction which is opposite to the charge if the charge is + or toward the charge is a negative one

The four charge are identical so they produce the same field at the center of the square. But the four field cancel each other since the field given by two opposite charge cancel each other.

Soo the electric field at the center of the square is ZERO

make a sketch and you will easily see.

Answer 2

If the magnitude of the electric field produced by one chrge at point P is E then the electric field of all other 3 charges at P have the same magnitude . The difference is just in the dirrection of them. The electric field of charges at opposite corners has opposite dirrections so they cancel .
So the magnitude is zero!

Answer 3

four identical charges mean all charges are the same positive or negative.
the equation for electric field(E)is =k IqI/r² ,k=8.99x10^9
remember that E is vector
E net= E1+E2+E3+E4

the distance from every charge to center is sqrt(8),
first,take the top charge on the right and calculate E=+k q/8
then,take the bottom charge on the left ,E= -k q/8
negative bcoz it's oppsite to the direction of the first one..like this
+q1<------------*---------->-q2
so ,the E net for 1.2 =zero
do same thing with the others .you will get zero.
that mean the E at the center is equal to zero

Answer 4

Charge functions as an inverse square of the distance. Your problem becomes one of geometry, knowledge of which is assumed.

Answer 5

i think this is the most popular question. you can find its solution in book writen by H.R.Verma. e-copy of this book is also available