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Electricity and Magnetism

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Conductors and Electric Charges: Shocking Winter Day

EANDM-FD76MH

On a cold and dry winter day, you walk across the carpet with your favorite winter socks on and notice a large shock when you touch a friend. You decide to reproduce this experiment a few months later on a humid summer day and similar results are not produced. You are not able to shock your friend.

Which of the following is the best explanation as to why you are able to shock your friend on the winter day and not on the summer day?

A

Dry air is a conductor and therefore during the winter when you drag your socks across the carpet charges are being transferred from the carpet to you and accumulate until you touch your friend.

When you touch your friend, all the excess charges are transferred from you to your friend and a shock is the result. On the other hand, humid air is an insulator therefore the charge does not accumulate on you because it leaks to the humid air. Since no charge is accumulated you are not able to shock your friend.

B

Dry air is an insulator and therefore during the winter when you drag your socks across the carpet charges are being transferred from the carpet to you and they accumulate until you touch your friend.

When you touch your friend, all the excess charges are transferred from you to your friend and a shock is the result. On the other hand, humid air is a conductor therefore the charge does not accumulate on you because it leaks to the humid air. Since no charge is accumulated on, you are not able to shock your friend.

C

Since dry air is a conductor, charges are transferred from the air to you on dry winter days.

When you touch your friend, the shock is a result of the excess charge being transferred from you to your friend. There is no charge transferred from the air to you on summer days because humid air is an insulator.

D

The humidity and conductivity of the air has nothing to do with the shock, cold air has free charges so there are more available when you touch your friend.

On the other hand, hot air has no free charges and therefore no charges available when you touch your friend so a shock is not possible