Physics Review Question

Unit: Electricity and Magnetism
Year: 1992
Question#: 20 Question: An object with +10 elementary charges is grounded and becomes neutral. What is the best explanation for this occurrence?

(1 ) The object gained 10 electrons from the ground.
(2 ) The object lost 10 electrons to the ground.
(3 ) The object gained 10 protons from the ground.
(4 ) The object lost 10 protons to the ground.

What is this question really asking?




Explanation by: Gabriel F
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Answer 1
A) The object gained 10 electrons from the ground.


CORRECT

This answer is right. Electrons are negative. So, if the object is positively charged and is grounded then the negative charges will neutralize it. The positive charges are usually not free to move since they contain the mass of the objects. 
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Answer 2
2) The object lost 10 electrons to the ground.

INCORRECT

A loss of 10 electrons would make the object +20 charged, not neutral.
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Answer 3
3) The object gained 10 protons from the ground

INCORRECT

This answer is wrong because a gain of 10 protons would make the object +20 charged.
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Answer 4
4)The object lost 10 protons to the ground.

INCORRECT

This would result in the neutral charge but under normal circumstances the positive charges are not free to move because they contain the mass of the material.
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What's this question really asking?

Which sub atomic particles are involved in charge transfer? return to top