Question

Exhibit 20-1

You have two metal spheres on insulating stands. You bring them each in turn near the ball of a positively charged electroscope. In each case the deflction of the leaves is reduced slightly. You then bring them each in turn near the ball of a negatively charged electroscope and find that sphere A causes the deflection to increase, whereas sphere B causes it to decrease.

7.Refer to Exhibit 20-1. Sphere A is

a. positively charged.

b. negatively charged.

c. neutral.

d. There is not enough information to determine this.

8.Refer to Exhibit 20-1. Sphere B is

a. positively charged.

b. negatively charged.

c. neutral.

d. There is not enough information to determine this.

9.A metal sphere on an insulating stand has a charge of 16 nC. A second metal sphere, also on an insulating stand, is initially uncharged. The two spheres are briefly touched together. The second sphere is then grounded. After this procedure, the charge on the original sphere is

a. 16 nC

b. 8 nC

c. 4 nC

d. 0 nC

e. more than 16 nC

f. There is not enough information to determine this

Answer 1

Answer 7 :- Option (b) is correct because when metal sphere A brings closer to the positively charged electroscope then it reduces the deflection which means it carry the charge opposite to this , and then  it brings near the negatively charged electroscope and find that the deflection increases which is only possible when metal sphere carries a similar charge as that of negatively charged electroscope so the Sphere A is negatively charged .

Answer 8 :- option c is correct because when metal sphere B brings closer to the positively charged electroscope then it reduced the deflection , and when it brings closer to the negatively charged electroscope it reduces the deflection which means it carries both charge positive and charge in equal amount which tell us that it is of neutral nature so the sphere B is neutral .

Answer 9:- Charge transfer always takes place from higher potential to lower potential unitl both carry the same potential .