Question

The potential difference between two points A and B is $10V$. Point A is at higher potential. If a negative charge, q = 2 C, is moved from point A to point B, then the potential energy of this charge will:

• A. decrease by 20 J
• B. decrease by 5 J
• C. increase by 5 J
• D. increase by 20 J
• E. increase by 100 J

Answer 1

Answer: (D)

increase by 20 J

The change in potential energy, $\Delta U=q\Delta V$

As the charge $q=-2C$ is moved from A to B so potential will decrease 10 V i.e $\Delta V=-10V$

Thus, $\Delta U=(-2)(-10)=+20J$