o v 2 1 V -1 V -2 V 1 2 V 3 V -3 V +q -q -1 -2 A -3 -3 -2 -1 2

The figure below shows the equipotential surfaces of a parallel plate capacitor. If a positive charge, q = +2 C, is moved between two equipotential surfaces (green surfaces: A and B) of an oppositely charged parallel plates (also known as parallel plate capacitor) as shown in the figure below, what is the change in the electric potential (AV), when the charge is moved from surface A to B? A. +3 V B. +9 V C. OV 2 cm D. - 3 V E. -9 V B ov qV ĞV 3V

Capacitance  Problem 3:  Two parallel plates have charges +Q and −Q, as shown. The magnitude of the charges is 29.7nC, the area of each plate is A=0.0105 m2, and the distance between them is d = 8.53cm. The plates are surrounded by air. Part (f)  If the area is doubled to 2A while the gap is decreased to 14d, then what is the value, in picofarads, of the new capacitance?  Part (g)  What is the new value, in volts, of potential difference between the plates with the original charges, +Q and −Q, given the increased area and reduced gap of Part (f)?

The figure below shows the equipotential surfaces of an electric dipole in the xy-plane. The x and y scales are in units of meter. The charge on the left is positive. Each color change represents a a change in the potential of 5 V. Estimate the magnitude and direction of the electric field in units of V/m N/C at x 13.5 m, y = 13.5 m. = 24.5 22.5 20.5 18.5 16.5 14.5 12.5 10.5 8.5 6.5 4.5 2.5 0.5 0.5 2.5 4.5 6.5 8.5 10.5 12.5 14.5 16.5 18.5 20.5 22.5 24.5

In the figure below, equipotential lines are shown at 1-m intervals. Suppose that V₁ = 7 V₁ V₂ = 14 V, V3 = 21 V, V4 = 28 V, and V5 = 35 V. OV V₁ V₂ A V3 I Submit B V₁ 0 m 1 m 2m 3m 4 m 5 m Submit V₂ 1) What is the electric field at point A? Enter a positive value if the electric field points in the +x direction and a negative value if if the electric field points in the -x direction. (Express your answer to two significant figures.) V/m 2) What is the electric field at point B? Enter a positive value if the electric field points in the +x direction and a negative value if if the electric field points in the -x direction. (Express your answer to two significant figures.) V/m