Electric Fields

Which statements about electric field lines are correct? Check all that apply. They point toward a positive charge. They point toward a negative charge. They point away from a positive charge. They point away from a negative charge. They cross over one another between charges. They never cross.

They point toward a negative charge. They point away from a positive charge. They never cross.

What is the direction of the electric field at a point directly below a negative charge, Q? up down left right

Up

The diagram shows the electric field in the vicinity of a charge. At which point is the electric field strongest? W X Y Z

Y

A source charge of 5.0 µC generates an electric field of 3.93 × 105 at the location of a test charge. How far is the test charge from the source charge? 0.11 m 0.34 m 1.1 m 3.4 m

0.34

A source charge generates an electric field of 1236 N/C at a distance of 4 m. What is the magnitude of the source charge? 2.2 µC 680 µC 2.2 C 680 C

2.2 µC

A charge of 0.05 C moves a negative charge upward due to a 2 N force exerted by an electric field. What is the magnitude and direction of the electric field? 0.03 upward 0.03 downward 40 upward 40 downward

40 downward

A +0.05 C charge is placed in a uniform electric field pointing downward with a strength of 100 . Determine the magnitude and direction of the force on the charge. 5 N downward 5 N upward 2000 N downward 2000 N upward

5 N downward

A point charge is placed 100 m from a 6 µC charge generating an electric field. What is the strength of the electric field on the point charge? (Round to the nearest whole number.)

5 N/C

A charge of +0.08 C moves to the right due to a 4 N force exerted by an electric field. What is the magnitude and direction of the electric field? 0.32 N/C left 0.32 N/C right 50 N/C left 50 N/C right

50 N/C right

Inside a television picture tube there is a build-up of electrons (charge of 1.602 × 10-19 C) with an average spacing of 38.0 nanometers between electrons. Find the electric field inside the picture tube. (Round to three significant figures.)

997,000 N/C

The diagram shows the electric field due to point charge Q. The negative charge, A, is within the field. Which statements are correct? Check all that apply. Charge Q is positive. Charge Q is negative. The electric field is uniform. The electric field is nonuniform. If charge A is negative, it moves away from charge Q. If charge A is positive, it moves away from charge Q

Charge Q is negative The electric field is nonuniform. If charge A is negative, it moves away from charge Q.

What formula gives the strength of an electric field, E, at a distance from a known source charge? E = E = E = E =

E = kq/ d^2

Two charges are in close proximity to one another. Describe electric field lines and the rules for diagraming field lines between two charges.

Electric field lines are lines drawn on a diagram of charged particles indicating the direction of the flow of the field. The lines originate at a positive point charge and end at a negative point charge. They do not cross each other and the density of the lines indicates the strength of the electric field.

The three diagrams show electric field lines around a pair of like charges. Which diagram shows a net force of zero on the charge placed at point X? Image 1 Image 2 Image 3

Image 3

Which best describes the electric field created by a positive charge? It circles clockwise around the charge. It circles counterclockwise around the charge. Its rays point away from the charge. Its rays point toward the charge.

Its rays point away from the charge.

What is the direction of the electric field at a point directly to the left of a positive charge, Q? up down left right

Left

The diagram shows the electric field due to point charge Q. Which statements are correct? Check all that apply. The electric field is nonuniform. The electric field is uniform. Charge Q is negative. Charge Q is positive. If charge A moves toward charge Q, it must be a negative charge. If charge A moves toward charge Q, it must be a positive charge.

The electric field is nonuniform. Charge Q is positive. If charge A moves toward charge Q, it must be a negative charge.

A negative test charge experiences a force to the right as a result of an electric field. Which is the best conclusion to draw based on this description? 1. The electric field points to the left because the force on a negative charge is opposite to the direction of the field. 2. The electric field points to the right because the force on a negative charge is in the same direction as the field. 3. No conclusion can be drawn because the sign of the charge creating the field is unknown. 4. No conclusion can be drawn because the amount of charge on the test charge is unknown.

The electric field points to the left because the force on a negative charge is opposite to the direction of the field.