Exam 20: Electric Potential and Electric Potential Energy

Three equal charges of magnitude + 4.00 μC are placed at the corners of an equilateral triangle of side 2.00 cm. What is the electric field potential energy of the system of these charges?

FIGURE 20-12 -Two point charges of magnitude +4.00 μC and -4.00 μC are placed as shown in Figure 20-12. An additional charge of magnitude +2.00 μC is placed at point A. What is the electric potential energy of this system of charges?

The direction of an electric field is from higher to lower potential.

Point charges of + 2.0 μC, + 4.0 μC, and + 6.0 μC are placed at the origin, the point y = -0.30 m, and x = 0.40 m, respectively. What is the electric potential energy of the system?

A +8.00-μC charge is situated along the +y-axis at y = 0.400 m. What is the electric potential at the origin because of this charge?

A 4.0-μC charge is situated at the origin of an xy-coordinate system. What is the potential difference between a point x = 4.0 m and y = -4.0 m because of this charge?

FIGURE 20-11 -The absolute value of the electric potential at a distance of 4 m from a certain point charge is 200 V. What is the absolute value of this potential at a distance of 2 m from the same charge?

FIGURE 20-11 -Three point charges of -2.00 μC, +4.00 μC, and +6.00 μC are placed along the x-axis as shown in Figure 20-11. What is the electrical potential at point P due to these charges?

A 2000 V/m electric field is directed along the +x-axis. If the potential at x = 10 m is 800 V, what is the potential at x = 6 m?

The potential difference between the plates of a parallel plate capacitor is 4.00 V. If the plate separation for this capacitor is 6.00 cm, what is the intensity of the electric field between the plates of this capacitor?

FIGURE 20-7 -Two identical charges of magnitude 6.0 μC are placed at the corners of the base of an equilateral triangle, as shown in Figure 20-7. What is the electric potential at the vertex, P, of the triangle due to these charges?

FIGURE 20-9 -Two point charges of +2.00 μC and +4.00 μC are placed at the origin and at y = -0.300 m, as shown in Figure 20-9. What is the electric field potential at a point P at a position x = 0.400 m due to these charges?

The electric field between the plates of a parallel plate capacitor is inversely proportional to the plate separation.

The potential energy at x = 8 m is -2000 V and at x = 2 m is +400 V. What is the magnitude and direction of the electric field?

A negative charge is moved from point A to point B along an equipotential surface. Which of the following statements is true for this case?

The electric potential at a point P due to a positive charge is along the direction of that charge.

FIGURE 20-10 -Two point charges of magnitude +4.00 μC and +2.00 μC are placed at the opposite corners of a rectangle as shown in Figure 20-10. What is the potential at point B due to these two charges?

Which of the following will increase the capacitance between the plates of a parallel plate capacitor?

The absolute value of the electric potential at a distance of 4 m from a certain point charge is 200 V. What is the absolute value of this potential at a distance of 8 m from the same point charge?

An electron, initially at rest is accelerated through a potential difference of 550 V. What is the speed of the electron due to this potential difference?