Potential Difference — Prelims Questions

The work done in moving a charge of $5\,C$ from a point at $20\,V$ to another point at $70\,V$ is:

An electron is accelerated from rest through a potential difference of $100\,V$. What is its gain in kinetic energy?

If the electric potential is given by $V(x) = 3x^2 - 2x$, what is the magnitude of the electric field at $x = 1\,m$?

Two points A and B are located at distances $r_A = 1\,m$ and $r_B = 3\,m$ from a point charge $Q = +6\,nC$. What is the potential difference $V_B - V_A$? (Take $k = \frac{1}{4\pi\epsilon_0} = 9 \times 10^9\,Nm^2/C^2$)

Which of the following statements about equipotential surfaces is FALSE?

A parallel plate capacitor has plates separated by $2\,mm$. If the potential difference across the plates is $200\,V$, what is the magnitude of the uniform electric field between the plates?