Physics 222 Worksheet: Chapter 17, (1) Energy and Potential

1) The potential difference between points A and B is:

a) The force required to move a unit charge from A to B.

b) The work required to move a unit charge from A to B.

c) The electric charge at A minus the electric charge at B.

d) The electric field at A minus the electric field at B.

2) Which of the following statements is true?

a) Electric field is a vector and potential is a scalar.

b) Electric field is a scalar and potential is a vector.

c) Electric field and potential are both vectors.

d) Electric field and potential are both scalars.

3) When a negative charge moves from a point of higher potential to a lower potential it

a) gains potential energy.

b) loses potential energy.

c) undergoes no change of potential energy.

4) A volt is the same as a

a) N/C

b) J/N

c) W/s

d) J/C

5) The eV is a unit of

a) potential

b) electric field

c) energy

d) charge

6) The voltage across a 2 mF capacitor holding 8 mC of charge is

a) 16 v

b) 4v

c) 0.25 v

d) 10 v

7) Which of the following will not increase the capacitance of an air capacitor?

a) Adding a dielectric in the space between the plates.

b) Increasing the area of the plates.

c) Moving the plates closer together.

d) Increasing the voltage.

8) An electron is released midway between two equally and oppositely charged plates.

a) It will move toward the positive plate.

b) It will move toward the negative plate.

c) It will not move at all.

9) Which of the following statements is not true about equipotential lines?

a) They begin on positive charges and end on negative.

b) The potential is the same at any point on a line.

c) They are perpendicular to electric field lines.

d) Different lines at different places in a drawing may not represent the same potential.

Ans: 1-b, 2-a, 3-a, 4-d, 5-c, 6-b, 7-d, 8-a, 9-a

Physics 222 Worksheet: Chapter 17, (2) Electric Energy and Potential

1) Potential energy per unit charge is called:

a) electric force

b) electric field

c) electric potential

d) electric charge

2) When a positive charge moves from a region of high potential to one of low potential

a) it must gain potential energy.

b) it must lose potential energy.

c) it must speed up.

d) it must slow down.

3) Volt is the proper unit for

a) charge.

b) electric field.

c) potential difference.

d) electric energy.

4) The potential 10 cm from a point charge is +60 v. At a distance of 20 cm the potential is:

a) 120 v

b) 240 v

c) 30 v

d) 15 v

5) When a charged particle moves in an opposite direction to the influence of the electric field

a) it must gain potential energy.

b) it must lose potential energy.

c) it must speed up.

d) it must slow down.

6) Farad is the unit of

a) capacitance

b) potential

c) electric field

d) electric charge

7) eV is a unit of

a) charge.

b) electric field.

c) potential difference.

d) energy.

8) The product of charge times the potential difference through which it moves gives

a) the electric force acting on the charge.

b) the electric field near the charge.

c) the change in the charge’s potential energy.

d) the change in the charge’s kinetic energy.

9) When 2 C of charge passes through an 8 v battery, the energy delivered is

a) 16 J

b) 4 J

c) 0.25 J

Ans: 1-c, 2-b, 3-c, 4-c, 5-a, 6-a, 7-d, 8-c, 9-a

Physics 222 Worksheet: Electrical Energy

In each problem, the charge qt is assumed to move under the influence of stationary charge Qs only. This means no gravity, no air resistance, nor anything else. Initially qt may be in motion.