1. Human skin must have a net positive charge: True False 2. On a cool, dry day
ID: 1635794 • Letter: 1
Question
1. Human skin must have a net positive charge: True False
2. On a cool, dry day you pick up a neutrally charged hard rubber comb to groom your dry, neutrally charged hair.
(a) After you finish combing your hair, there is a net charge on the comb. Why?
(b) Is the charge on the comb positive or negative?
* If you chose positive, how do you know it shouldn’t have been negative?
* If you chose negative, how do you know it shouldn’t have been positive?
3. After grooming your hair on a dry day with the hard rubber comb mentioned in Question 1, you notice that the comb can attract small, neutrally charged pieces of paper. Explain why the neutral objects are attracted to the comb.
4. After grooming your hair on a humid day with the hard rubber comb mentioned in Question 1, you notice that small, neutrally charged pieces of paper are not attracted to the comb. Please explain why the neutral objects respond differently to the comb on humid days than they do on dry days.
Explanation / Answer
1) false, our skin has no net electric charge. Any effect u see is due to triboelectric effects produced due to rubbing.
2) charge on comb is due to rubbing action. Loosely held electrons of hairs get transferred to comb. And comb becomes charged.
Charge on comb will be negative. It's material property . Hairs will loose electrons to comb. So comb will get negative charge and hairs will be +vely charged.
3)Papers are electrically neutral. But when the are brought under electric field of comb, small paper pieces get polarised, and hence get attracted.
4.On a humid day, rubing creates charge, but charge gets dissipated to humid environment faster than dry days. So electric field are so insignificant that we can't see such effects which we were seeing on dry days
.I hope this was helpful. Feel free to ask your queries below. And please rate me If you found it helpful. Thanks.
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