Exam 21: Electric Potential

The three point charges shown in the figure form an equilateral triangle with sides 4.9 cm long. What is the electric potential (relative to infinity) at the point indicated with the dot, which is equidistant from all three charges? Assume that the numbers in the figure are all accurate to two significant figures. (k = 1/4πε₀ = 9.0 × 10⁹ N ∙ m²/C²)

An ideal parallel-plate capacitor has a capacitance of C. If the area of the plates is doubled and the distance between the plates is halved, what is the new capacitance?

The equipotential surfaces for two spherical conductors are shown in the figure, with the value of potential marked on the line for each surface. (a) If the distance between points A and B is 2.5 cm what is the approximate intensity of the electric field between these two points? (b) If the distance between points C and D is 2.5 cm what is the approximate intensity of the electric field between these two points?

A proton that is initially at rest is accelerated through an electric potential difference of magnitude 500 V. How much kinetic energy does it gain? (e = 1.60 × 10^-19 C)