In the diagram below the red dot denotes a positive point charge. Points W, X, Y
ID: 1404776 • Letter: I
Question
In the diagram below the red dot denotes a positive point charge. Points W, X, Y, and Z and the point charge lie in the same plane. Points W and Y are equidistant from the charge, as are points X and Z.
A particle with charge -qe travels from W to X to Z along the path shown. Which of the statements below is true?
1. The work done by the electric field from W to X is negative.
2. The particle travels across a potential difference ?VWX which has the same magnitude but opposite sign as the potential difference ?VWX for a positive charge +qe.
3. If we would double the charge to -2qe, the potential difference ?VWX would double.
4. The potential difference is defined as the negative of the work done by the electric field on a test charge q, divided by q.
Only statement 1 is true
Only statement 2 is true.
Statements 1 and 4 are true.
All statements are true.
Only statement 4 is true.
a.Only statement 1 is true
b.Only statement 2 is true.
c.Statements 1 and 4 are true.
d.All statements are true.
e.Only statement 4 is true.
Explanation / Answer
The charge is positive, so the electric field lines show that field is to infinity from the charge. It is like outward. Now if we move a negative charge from point of the positive charge (W) to the X so the direction is along the field direction then work must be done against the electric field in moving the charges apart. So work is said to be negative. The magnitude of potential difference add up when positive charge is taken. The third one is wrong as the potential is reduced to half. It does not double. The definition of potential is the negative work done in moving a positive test charge from infinity to a point in the field. negative indicate the direction of motion of the test charge with the field. So correct answer is statement 1 & 4 are true.