Question

Find the potential difference between the final and initial points.

• A. $-4\times {10}^{3}V$
• B. $-4\times {10}^{4}V$
• C. $4\times {10}^{3}V$
• D. $4\times {10}^{4}V$

Answer 1

The correct option is B $-4\times {10}^{4}V$

Since the field is uniform, the potential difference will be given by the product of the electric field and the distance. so it will be $8\times 0.5\times {10}^4=4\times {10}^{4}V$

Proton being positively charged will always move from higher potential to a lower potential. Since it is stated as PD between final and initial, it is lower-higher, hence it is negative.