ch23

c>a>b E = -∆V/∆x, so the magnitude of the electric field (E) is greatest when the potential (V) changes most rapidly with position (x). This occurs at Point C. The potential is constant around Point B, which means the electric field is zero there.

Part complete The graph in (Figure 2) plots the potential as a function of position along the x axis. a,b,c?

C)The electric potential energy of the charge decreases, and the kinetic energy increases.

A negative charge moves in a direction opposite to that of an electric field. What happens to the energy associated with the charge? A)Both the electric potential energy and the kinetic energy of the charge increase. B)Both the electric potential energy and the kinetic energy of the charge decrease. C)The electric potential energy of the charge decreases, and the kinetic energy increases. D)The electric potential energy of the charge increases, and the kinetic energy decreases.

B)The potential energy associated with the charge increases. C)The electric field does negative work on the charge.

A negative charge moves in the direction of an electric field. Which of the following statements are true? pick all that apply. A)The electric field does positive work on the charge. B)The potential energy associated with the charge increases. C)The electric field does negative work on the charge. D)The amount of work done on the charge cannot be determined without additional information. E)The potential energy associated with the charge decreases. F)The electric field does not do any work on the charge.

North>East>south

A negatively charged object is located in a region of space where the electric field is uniform and points due north. The object may move a set distance d to the north, east, or south. Rank the three possible movements by the change in electric potential energy (Ue) of the object. North south east?

C)No work is performed or required in moving the positive charge from point A to point B. an equipotential surface is same voltage along a line work= q∆V ∆V=0

A positive charge is moved from point A to point B along an equipotential surface. How much work is performed or required in moving the charge? A)Work is required in moving the positive charge from point A to point B. B)Work is both performed and required in moving the charge from point A to point B. C)No work is performed or required in moving the positive charge from point A to point B. D)Work is performed in moving the positive charge from point A to point B.

B)The electric potential energy of the charge increases and the kinetic energy decreases

A positive charge moves in a direction opposite to that of an electric field. What happens to the energy associated with the charge? A)Both the electric potential energy and the kinetic energy of the charge increase. B)The electric potential energy of the charge increases, and the kinetic energy decreases. C)The electric potential energy of the charge decreases, and the kinetic energy increases. D)Both the electric potential energy and the kinetic energy of the charge decrease.

C)The electric field does positive work on the charge. E)The potential energy associated with the charge decreases.

A positive charge moves in the direction of an electric field. Which of the following statements are true? pick all that apply. . A)The electric field does negative work on the charge. B)The potential energy associated with the charge increases. C)The electric field does positive work on the charge. D)The electric field does not do any work on the charge. E)The potential energy associated with the charge decreases.

B)VD C)VB

The figure shows the electric potential V at five locations in a uniform electric field. At which points is the electric potential equal? Check all that apply. A)VA B)VD C)VB D)VE E)VC

E)2.5 × 10-18 J Potential difference is defined as the change in electric potential energy per charge: ΔV=ΔUeq. So the change in electric potential energy is ΔUe=qΔV. From part B, the potential at y3 was determined to be 9.1 V, so the potential difference between y1 and y3 is ΔV=9.1 V−1.3 V=7.8 V. The change in electric potential energy of the alpha particle is ΔUe=2(1.6×10−19 C)(7.8 V)=2.5×10−18 J. Just like you saw in the video, this is a small amount of energy in joules, because the alpha particle has very little mass. You could convert this energy from joules to electron-volts to express the kinetic energy in more appropriate units: ΔUe=2.5×10−18 J(1 eV1.6×10−19 J)=15.6 eV.

In a region where there is a uniform electric field, the potential, V1, is 1.3 V at position y1=26 cm. At position y2=28 cm, the potential, V2, is 3.9 V. What is the change in electric potential energy of an alpha particle (charge = +2e) if it is moved from y1 to y3? In a region where there is a uniform electric field, the potential, V1, is 1.3 V at position . At position , the potential, V2, is 3.9 V. What is the change in electric potential energy of an alpha particle (charge = +2e) if it is moved from y1 to y3? The figure shows three positions labeled as y subscript 1, y subscript 2, and y subscript 3 from top to bottom. The potentials V subscript 1, V subscript 2 and V subscript 3 correspond to the positions y subscript 1, y subscript 2, and y subscript 3, respectively. A)2.9 × 10-18 J B)1.2 × 10-18 J C)4.2 × 10-19 J D)8.3 × 10-19 J E)2.5 × 10-18 J

A)1.3 V/cm For a uniform electric field, the magnitude of the y-component of the electric field is equal to the ratio of the potential difference to the distance between the points where the potential is measured: Ey=ΔVΔy. So E=V2−V1y2−y1=3.9 V−1.3 V28 cm−26 cm=1.3 V/cm.

In a region where there is a uniform electric field, the potential, V1, is 1.3 V at position y1=26 cm. At position y2=28 cm, the potential, V2, is 3.9 V. What is the magnitude of the y-component of the electric field in this region? A)1.3 V/cm B)5.2 V/cm C)0.77 V/cm D)0.050 V/cm E)0.14 V/cm

B)9.1 V For a uniform electric field, the magnitude of the y-component of the electric field is equal to the ratio of the potential difference to the distance between the points where the potential is measured: Ey=ΔVΔy. So E=V2−V1y2−y1=3.9 V−1.3 V28 cm−26 cm=1.3 V/cm.

In a region where there is a uniform electric field, the potential, V1, is 1.3 V at position y1=26 cm. At position y2=28 cm, the potential, V2, is 3.9 V. What is the potential at position y3=32 cm? In a region where there is a uniform electric field, the potential, V1, is 1.3 V at position . At position , the potential, V2, is 3.9 V. What is the potential at position ? The figure shows three positions labeled as y subscript 1, y subscript 2, and y subscript 3 from top to bottom. The potentials V subscript 1, V subscript 2 and V subscript 3 correspond to the positions y subscript 1, y subscript 2, and y subscript 3, respectively. A)6.5 V B)9.1 V C)7.8 V D)42 V E)1.5 V

A)At twice the distance, the electric potential is V/2.

The electric potential at a certain distance from a point charge can be represented by V. What is the value of the electric potential at twice the distance from the point charge? A)At twice the distance, the electric potential is V/2. B)At twice the distance, the electric potential is 4V. C)At twice the distance, the electric potential is V/4. D)At twice the distance, the electric potential remains V. E)At twice the distance, the electric potential is 2V.

B)If you triple the value of the charge, the electric potential is 3V.

The electric potential at a certain location from a point charge can be represented by V. What is the value of the electric potential at the same location if the strength of the charge is tripled? A)If you triple the value of the charge, the electric potential is 9V. B)If you triple the value of the charge, the electric potential is 3V. C)If you triple the value of the charge, the electric potential is V/9. D)If you triple the value of the charge, the electric potential is V/3. E)If you triple the value of the charge, the electric potential remains V.

E)VA

The figure shows the electric potential V at five locations in a uniform electric field. At which point is the electric potential the largest? A)VB B)VE C)VC D)VD E)VA

B)An equipotential surface is a three-dimensional surface on which the electric potential is the same at every point D)When all charges are at rest, the surface of a conductor is always an equipotential surface. E)Electric field lines and equipotential surfaces are always mutually perpendicular.

Which of the following statements are true? Check all that apply. A)The potential energy of a test charge increases as it moves along an equipotential surface. B)An equipotential surface is a three-dimensional surface on which the electric potential is the same at every point. C)The potential energy of a test charge decreases as it moves along an equipotential surface. D)When all charges are at rest, the surface of a conductor is always an equipotential surface. E)Electric field lines and equipotential surfaces are always mutually perpendicular.

Electric field lines are always perpendicular to equipotential surfaces and point in the direction of decreasing potential.

diagrams correctly represents the electric field lines corresponding to the equipotential surfaces?

D)Path a to b The work (W) is the negative of the change in the electric potential energy (∆Ue), and ∆Ue equals the product of the charge (q0) and the change in the electric potential (∆V): W = -∆Ue = -q0∆V = -q0(Vfinal - Vinitial). Path a to b has the greatest decrease in V, which leads to the greatest decrease in Ue and the greatest amount of work done on the particle.]

shows four equipotential surfaces. The positively charged particle located at Point a can move to Points b, c, or d by the paths indicated. Along which path is the greatest work done on the particle by the electric field? A)The work done is equal along all three paths. B)Path a to d C)Path a to c D)Path a to b