Question

In the figure, a proton moves a distance $d$ in a uniform electric $\vec{ E }$ as shown in the figure. Does the electric field do a positive or negative work on the proton? Does the electric potential energy of the proton increase or decrease?

• A. Negative, increase
• B. Positive, decrease
• C. Negative, decrease
• D. Positive, increase

Answer 1

Answer: (A)

Since, the proton is moving against the direction of electric field, so work is done by the proton against electric field. It implies that electric field does negative work on the proton. Again, proton is moving in electric field from low potential region to high potential region hence, its potential energy increases.