Question

C.
Work function
9. The potential energy has a negative sign because the potential energy at any given point
is than its value at infinity.
a) Zero
b) One
c) Less
d) Greater
1 to​

Answer 1

Answer:

The work is given by:

Note that if q is negative, its sigh should be used in the equation! Therefore, a system consisting of a negative and a positive point-like charge has a negative potential energy.

A negative potential energy means that work must be done against the electric field in moving the charges apart!

Now consider a more general case, which deals with the potential in the neighborhood of a number of charges as depicted in the picture below:

Let r1,r2,r3 be the distances of the charges to a field point A, and r12, r13, r23 represent the distance between the charges. The electric potential at point A is: