Posted by **Robert** on Tuesday, August 14, 2012 at 11:55pm.

A charge +q is at the origin. A charge –2q is at x = 2.00 m on the x axis. For what finite value(s) of x is (a) the electric field zero? (b) the electric potential zero?

- Physics - Electromagnetism -
**Elena**, Wednesday, August 15, 2012 at 8:43am
Let the point where E=0 be to the left from the charge q and separated by distance “x” from q and by distance (2+x) from -2q. Then

kq/x²=k2q/(2+x)²,

x²-4x-4 = 0

x= 2±√(4-4) =2.

The point where E=0 is x= - 2m.

Let the point where φ=0 be to the right from q and separated by distance x from it.

kq/x =k2q/(2-x),

x=2/3 m

The point where φ =0 is x=+ 2/3 m.

## Answer this Question

## Related Questions

- physics - electric field - a point particle with charge q= 4/5 uC is placed on ...
- physics - electric field - a point particle with charge q= 4/5 uC is placed on ...
- Physics - A point charge Q1=-2 microcoulomb is located at x=0, and a point ...
- Physics - A charge q1 = 5 ěC is at the origin. A second charge q2 = -3 ěC is on ...
- Physics - Two charges are D = 1.5 m apart and lie on the x-axis. What must be ...
- physics - please check: Two point charges, initially 1 cm apart, are moved to a ...
- Physics - Suppose you have a 5nC charge T the origin and a 2nC charge at x=5m. ...
- gen. physics II - A charge of +3 C is at the origin. When charge Q is placed at...
- electromagnetism - a line of charge staarts at x=+×and extends to positive ...
- physics - PART ONE: A charge of 4.70μC is at the origin and a second charge...

More Related Questions