PHYSICS

JAMB 2018 - Question 28

Physics 2018 JAMB Past Questions - Question 28: A positive charged rod X is brought near an uncharged metal sphere Y and is then touched by a finger with X still in place. When the finger is removed, the result is that Y has

Choose the correct answers from the options given.
A positive charged rod X is brought near an uncharged metal sphere Y and is then touched by a finger with X still in place. When the finger is removed, the result is that Y has
A:
B:
C:
D:
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Correct Answer

D

Explanation

The metal sphere Y now carries a positive charge. When the positively charged rod X is brought near the uncharged metal sphere Y, it induces a negative charge on the side of the sphere closest to it and repels positive charges to the opposite side. When you touch it with your finger, electrons flow from your finger to the sphere, neutralizing the induced negative charge. However, since the positive rod is still nearby, it repels some electrons, leaving the sphere with a net positive charge once your finger is removed.