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Nilanjan Bhowmick AIR 3, CSIR NET (Earth Science)
- IIT JAM
- Physics (PH)
Electricity and magnetism
I read these type of statements many time But what was the reason. behind this please explain me one by one. Also from the last pic where a positive charge in the direction of electric........
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Dhairya sharma
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this is from F = qE. field does positive work on +ve charge moving in the direction of field. while for negative charge it's opposite
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Abhishek singh
Again read the whole solution. I have added the solution for 3rd and 4th pic as well. do think on each word.
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you got stuck in any concepts. do read the whole solution from scratch.
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Then, you are free to ask further queries.
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this will surely clear your doubts for lifelong
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and sir also explain about last pic that how direction of charge decides that work is done on the charge or by the charge ?????
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Okay, see my next comment! you will definately get it.
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Abhishek singh Best Answer
electric field is always directed from higher potential to lower potential. and work done is positive when angle between force and displacement is less then 90°, otherwise work done is negative.(because of cos(theta) term due to dot product). Best regards.
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do ask doubts.
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and for remaining two pictures, see my next comments
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read this solution first.
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Dhairya sharma
it's because F = qE
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Abhishek singh![best-answer]()
Explanation of last pic(Handwritten): See your first fir, now tell me, in this case positive charge is movinge along the electric field. it means you(external agent) have to do nothing to move that charge along electric field that's why work is done by the charge itself. Now se your second diagram, here positive charge is moving opposite to electric field, is it natural? what you think is the tandency of that charge to move along?(ofcourse along electric field direction). But it is not doing so! it means some external agent has to do work on the charge to move it opposite to electric field, right? Hope this helps! Best regards.
Some typos in the comment, first pic**....... Now see your***.... what do you think****