Electric Fields & Forces

The Electric Field Charges create an electric field around them. In thunderclouds, the field can be strong enough to ionize air, causing lightning.

Question 1 Coulomb’s law describes The electric field due to a point charge. The force between two point charges. The electric field due to a charged rod. The electric potential of a point charge. Answer: B

Question 1 Coulomb’s law describes The electric field due to a point charge. The force between two point charges. The electric field due to a charged rod. The electric potential of a point charge.

Question 2 The field inside a charged parallel-plate capacitor is Zero. Uniform. Parallel to the plates. Directed from the negative to the positive plate. Answer: B

Question 2 The field inside a charged parallel-plate capacitor is Zero. Uniform. Parallel to the plates. Directed from the negative to the positive plate.

Question 3 The electric field inside a metallic conductor is Positive. Negative. Zero. Answer: C

Question 3 The electric field inside a metallic conductor is Positive. Negative. Zero.

Question 4 Metal spheres 1 and 2 are touching. Both are initially neutral. The charged rod is brought near. The charged rod is then removed. The spheres are separated. Afterward, the charges on the sphere are: Q1 is + and Q2 is + Q1 is + and Q2 is – Q1 is – and Q2 is + Q1 is – and Q2 is – Q1 is 0 and Q2 is 0 Answer: E 9

Question 4 Metal spheres 1 and 2 are touching. Both are initially neutral. The charged rod is brought near. The charged rod is then removed. The spheres are separated. Afterward, the charges on the sphere are: Q1 is + and Q2 is + Q1 is + and Q2 is – Q1 is – and Q2 is + Q1 is – and Q2 is – Q1 is 0 and Q2 is 0 10

Question 5 Metal spheres 1 and 2 are touching. Both are initially neutral. The charged rod is brought near. The spheres are separated. The charged rod is then removed. Afterward, the charges on the sphere are: Q1 is + and Q2 is + Q1 is + and Q2 is – Q1 is – and Q2 is + Q1 is – and Q2 is – Q1 is 0 and Q2 is 0 Answer: C 11

Question 5 Metal spheres 1 and 2 are touching. Both are initially neutral. The charged rod is brought near. The spheres are separated. The charged rod is then removed. Afterward, the charges on the sphere are: Q1 is + and Q2 is + Q1 is + and Q2 is – Q1 is – and Q2 is + Q1 is – and Q2 is – Q1 is 0 and Q2 is 0 Net charge is obtained if contact is broken while the spheres are polarized. This is charging by induction. 12

Question 6 Based on the last experiment, where two spheres were charged by induction, we can conclude that Only the – charges move. Only the + charges move. Both the + and – charges move. We can draw no conclusion about which charges move. Answer: D 13

Question 6 Based on the last experiment, where two spheres were charged by induction, we can conclude that Only the – charges move. Only the + charges move. Both the + and – charges move. We can draw no conclusion about which charges move. 14

Question 7 Identical metal spheres are initially charged as shown. Spheres P and Q are touched together and then separated. Then spheres Q and R are touched together and separated. Afterward the charge on sphere R is: –1 nC or less –0.5 nC 0 nC +0.5 nC +1.0 nC or more Answer: C 15

Question 7 Identical metal spheres are initially charged as shown. Spheres P and Q are touched together and then separated. Then spheres Q and R are touched together and separated. Afterward the charge on sphere R is: –1 nC or less –0.5 nC 0 nC +0.5 nC +1.0 nC or more 16