ch33.ppt

Multiple Choice

Why is the concept of an electric field considered significant in physics?

• Because it explains how charges interact at a distance

• Because it is only relevant to magnets

• Because it is unrelated to energy storage

• Because it only applies to moving charges

Open Ended

Describe what happens when you walk by the charged dome of a Van de Graaff generator. Why do you think this occurs?

Multiple Choice

What determines the direction of an electric field at any point?

• The direction of the electrical force on a small positive test charge

• The direction of the electrical force on a small negative test charge

• The direction of the magnetic force

• The direction of the gravitational force

Open Ended

Explain how the concept of a force field allows Earth to exert a force on objects without direct contact. Use the analogy of a ball thrown upward.

Open Ended

Describe what happens when a person approaches a charged Van de Graaff generator. What does this demonstrate about electric fields?

Multiple Select

Which of the following statements about electric fields are correct?

• An electric field surrounds an electric charge

• Electric fields can exert forces without physical contact

• Electric fields only exist around negative charges

• Electric fields can interact with other electric fields

Multiple Choice

Which of the following best describes the relationship between gravitational and electrical forces as shown in the diagrams?

• Both forces act at a distance and hold objects in orbit

• Gravitational force only acts on planets, electrical force only acts on electrons

• Electrical force is stronger than gravitational force in all cases

• Gravitational force requires contact, electrical force does not

Multiple Choice

What does the magnitude of an electric field depend on?

• The effect on charges located in the field

• The color of the field

• The temperature of the environment

• The size of the test charge

Open Ended

Explain how the direction of an electric field is determined for both positive and negative charges.

Multiple Select

Which of the following statements about electric field vectors are correct?

• A negatively charged particle is surrounded by vectors that point toward the particle.

• For a positively charged particle, the vectors point away.

• Magnitude of the field is indicated by the vector length.

• Vectors always point away from both positive and negative charges.

Open Ended

Describe how electric field lines behave for isolated charges and for two or more opposite charges.

Multiple Choice

What does it mean when electric field lines are farther apart?

• The field is weaker

• The field is stronger

• The field is neutral

• The field is changing direction

Open Ended

Explain the difference between the vector representation and the lines-of-force representation of electric fields.

Multiple Choice

Which representation uses the length of vectors to indicate the magnitude of the electric field?

• Vector representation

• Lines-of-force representation

• Scalar representation

• Potential representation

Open Ended

Describe the pattern of electric field lines between two oppositely charged capacitor plates.

Multiple Select

Which of the following statements about electric field lines is/are correct?

• Field lines around a positive charge extend to infinity.

• For a pair of equal but opposite charges, field lines go from positive to negative charge.

• Field lines are evenly spaced between two oppositely charged capacitor plates.

• Field lines form closed loops around a single charge.

Multiple Choice

What does the photo in the last image demonstrate about electric field patterns for equal and opposite charges?

• The field lines are parallel and evenly spaced.

• The field lines curve from one charge to the other, showing attraction.

• The field lines form closed loops around each charge.

• The field lines are absent between the charges.

Multiple Choice

Which of the following diagrams best represents the electric field pattern between two oppositely charged parallel plates?

• Diagram a

• Diagram b

• Diagram c

• Diagram d

Open Ended

Describe how bits of thread suspended in an oil bath can be used to visualize electric field lines around charged conductors.

Multiple Choice

Which of the following statements about the electric field between oppositely charged parallel plates is correct?

• The field lines are curved and non-uniform.

• The field lines are nearly parallel and the field is of constant strength except near the ends.

• There is no electric field between the plates.

• The field lines point away from both plates.

Open Ended

Explain why there is no electric field inside a charged cylinder according to the information provided.

Open Ended

Reflecting on what you learned about electric fields, how would you explain the concept of a force field to someone who has never heard of it before?