HW. Electric Fields and Electric Energy

In the diagram below, P is a point near a negatively charged sphere. Which direction best represents the direction of the electric field at point P?

• Right
• Left
• Up 
• Down

Which quantity and unit are correctly paired?

• electric field strength and N/C
• electricity and Coulombs
• electrostatic force and electrons
• electric field strength and E

A point charge Q is far from all other charges. At a distance of 2 m from Q, the electric field is 20 N/C. What is the force a charge of 5 Coulombs feels?

• 4 N
• 100 N
• 40 N
• 10 N

Which of the following statements is false about electric field lines

• electric field lines cannot cross
• electric field lines point away from positive charge
• electric field lines are always straight lines
• electric field lines show how a proton would move in an electric field

At which point is the electric field the strongest

• A
• B
• C
• D

At which point is the electric field the weakest?

• A because it is the furthest away
• A because the field lines are further apart
• C because the field lines are further apart
• C  because it is the furthest away

Consider the electric field lines shown in the diagram below. From the diagram, it is apparent that object A is ____ and object B is ____.

• +,+
• +,-
• -,+
• -,-

An electrostatic force of 2 X 10². newtons is exerted on a charge of 4 coulomb at point P in an electric field. The magnitude of the electric field intensity at P is

• 8 X 10² N/C
• 5 N/C
• 2 X 10^-2 N/C
• 50 N/C

It is observed that Balloon A is charged negatively. Balloon B exerts a repulsive effect upon balloon A. Would the electric field vector created by balloon B be directed towards B or away from B and why?

• towards because electric field lines point away from negative charges
• towards because electric field lines point away from positive charges
• away because electric field lines point away from negative charges
• away because electric field lines point toward positive charges

Q_A and Q_B are two charges creating an electric field. Based on the electric field lines, we can conclude

• Q_A and Q_B are both positive
• Q_A and Q_B are both negative
• Q_A is positive and Q_B is negative
• Q_A is negative and Q_B is positive