fisikavurahou gew 1

Two charged particles A and B are located near one another. Both the magnitude and direction of the force that particle A exerts on particle B is independent of

• the sign of charge B.

• the sign of charge A.

• the distance between A and B.

• the magnitude of the charge on B

• The magnitude and direction of the force are dependent on all of the above choices.

Complete the following statement: When an ebonite rod is rubbed with animal fur, the rod becomes negatively charged as

• positive charges are transferred from the fur to the rod.

• negative charges are transferred from the rod to the fur.

• negative charges are created on the surface of the rod.

• negative charges are transferred from the fur to the rod.

• positive charges are transferred from the rod to the fur.

Complete the following statement: When a glass rod is rubbed with silk cloth, the rod becomes positively charged as

• positive charges are transferred from the silk to the rod.

• negative charges are transferred from the rod to the silk.

• positive charges are created on the surface of the rod.

• negative charges are transferred from the silk to the rod.

• positive charges are transferred from the rod to the silk.

Which one of the following statements best explains why tiny bits of paper are attracted to a charged rubber rod?

• Paper is naturally a positive material.

• Paper is naturally a negative material.

• The paper becomes electrically polarized by induction.

• Rubber and paper always attract each other.

• The paper acquires a net positive charge by induction.

Two uncharged, conducting spheres, A and B, are held at rest on insulating stands and are in contact. A positively charged rod is brought near sphere A as suggested in the figure. While the rod is in place, someone moves sphere B away from A. How will the spheres be charged, if at all?

• positive positive

• positive negative

• negative positive

• negative negative

• zero zero

Three charges are positioned as indicated in the figure. What are the horizontal and vertical components of the net force exerted on the +15 μC charge by the +11 μC and +13 μC charges?

• 95 N 310 N

• 76 N 310 N

• 250 N 130 N

• 95 N 130 N

• 76 N 370 N

Five styrofoam balls are suspended from insulating threads. Several experiments are performed on the balls; and the following observations are made: I. Ball A attracts B and A repels C. II. Ball D attracts B and D has no effect on E. III. A negatively charged rod attracts both A and E. What are the charges, if any, on each ball?

• + - + 0 +

• + - + + 0

• + - + 0 0

• - + - 0 0

• + 0 - + 0

An aluminum nail has an excess charge of +3.2 μC. How many electrons must be added to the nail to make it electrically neutral?

• 2.0 X 10^13

• 2.0 X 10^19

• 3.2 X 10^16

• 3.2 X 10^6

• 5.0 X 10^-14

In Frame 1, two identical conducting spheres, A and B, carry equal amounts of excess charge that have the same sign. The spheres are separated by a distance d; and sphere A exerts an electrostatic force on sphere B that has a magnitude F. A third sphere, C, which is handled only by an insulating rod, is introduced in Frame 2. Sphere C is identical to A and B except that it is initially uncharged. Sphere C is touched first to sphere A, in Frame 2, and then to sphere B, in Frame 3, and is finally removed in Frame 4. Determine the magnitude of the electrostatic force that sphere A exerts on sphere B in Frame 4.

• F/2

• F/3

• 3F/4

• 3F/8

• zero

Determine the ratio of the electrostatic force to the gravitational force between a proton and an electron, FE/FG.

• 1.24 X 10^23

• 2.52 X 10^29

• 1.15 X 10^31

• 2.26 X 10^39

• 1.42 X 10^58