POP QUIZ 1 (CHAPTER 22-24)

When distance increases, electrostatic force ____________; we call this relationship ____________ proportional

• decreases;directly
• decreases;inversely
• increases;inversely
• increases;directly

Calculate the force exerted between two charged objects separated by a distance of 0.6 m. One object has a charge of -5 C and the other has a charge of +2.0 C.

• -1.5E-11 N
• 2.5E-11 N
• -2.5E11 N
• -7.5E-10 N

What is the total charge of 75.0 kg of electrons?

• 9.23 x 10^-7 C

• 4.78 x 10-⁷ C

• −1.32 × 10¹³ C

• −2.45 × 10⁷C

A student rubbed two different material non-metal with two different cloths.

He found that the two rods are attracted each other.

What is the most likely explanation?

• The combination of rods transferred charges so that one rod had more positive charges and more negative charges on the other.

• The combination of rods and cloths put positive charges onto both of the rods.

• The combination of rods and cloths put negative charges onto both of the rods.

• Both rods were neutral.

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

• 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 ____.

• +,+
• +,-
• -,+
• -,-

What does the Law of Conservation of Charge state?

• like charges repel and opposites attract

• positive charge fields point away from a charge; negative points toward

• charges cannot be created nor destroyed, only transferred

The electric flux Φ through a surface

• is the amount of electric field piercing the surface
• is the electric field multiplied by the area.
• does not depend on the area involved
• is the line integral of the electric field around the edge of the surface