List of top Physics Questions on Electric Potential and Electric Potential Energy asked in KEAM

A proton travels through a distance of $5\text{ m}$ in the direction of uniform electric field of intensity $4\text{ NC}^{-1}$. The work done on the proton by the electric field is

Two masses connected in series with two massless strings are hanging from a support as shown in the figure. Find the tension in the upper string.