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PHY101 - Physics Assignment No. 3 Solution and Discussion Spring 2017 Due Date: July 17, 2017
TOTAL MARKS: 25
Due Date: 17/07/2017
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Question. No: 1
a) A negatively charged rod is brought close to some small pieces of neutral paper. The positive sides of molecules in the paper are attracted to the rod and the negative sides of the molecules are repelled. Since negative and positive sides are equal in number, why don't the attractive and repulsive forces cancel out?
b) (a) If a drop of liquid has capacitance 1.00 pF, what is its radius? (b) If another drop has radius 2.00 mm, what is its capacitance? (c) What is the charge on the smaller drop if its potential is 100 V? Marks = 4 + 6 = 10
Question. No: 2
a) What happens to the current in other lamps if one of the lamps in a parallel circuit burns out?
b) What is the difference between magnetic flux and magnetic field?
c) A loop of wire is placed in a uniform magnetic field. For what orientation of the loop is the magnetic flux a maximum? For what orientation is the flux zero? Marks = 5 + 5 + 5 = 15
Only (A) part of question no. 1 is missing if someone solved it please share.
Q 1 ka part a ka solution da do koi mjhy to nae mil rha
the positive sides are simple closer to the rod. In accord with Coulomb's law,
they therefore experience a greater electrical force then the negative sides, which
are farther away. Hence we say that closeness wins. this greater force between positive and negative is attractive,
So the neutral paper is attracted to the charged rod.
can you see thzt, if the rod were positive, attraction would still occur?
The electric flux can be thought of as being proportional to the number of "field lines" passing through the loop. To maximize this you need to have the surface of the loop perpendicular to the field. When you start to the tip the loop, less area is exposed and so less field lines will pass through the loop.
If you take this to the extreme limit, when the loop is parallel to the field lined, then NO field is passing through the loop and there is no flux.