Physics'Paper

13 - ELECTROSTATICS
( Answers at the end of all questions )

Page 1

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Two point charges + 8q and - 2q are located at x 0 and lt L respectively. The location of a point on the x axis at which the net electric field due to these two point charges is zero is (a) Ll4 (b) 2L (c) 4L (d) 8L Two thin wire rings each having a radius R are placed at a distance axes coinciding. The charges on the two rings are + q and - q. The between the centres of the two rings is (a)-q- 1
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their

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(d) zero

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A parallel plate capacitor is made by stacking n n... alternatively. If the capacitance between any two capacitance Is (a)(n+1)C (b}(n-1}C (c)~ C

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plates connected is 'C', then the resultant

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A charged ball B hangs from a silk thre~ h. makes an angle & with a large conducting sheet P, as sho in figure. The surface charge density o of the sheet is pr to
(a) cot&

( b 1 cos e ( c) tan &
(d

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(d

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B and C having equal radii and carrying equal charges in them force F when kept apart at some distance. A third spherical

r having same radius as that of B but uncharged, is brought in contact with B, brought in contact with C and finally removed away from both. The new force of ,...,...:~a.repu lsi on between B and C is aI FI4 ( b I 3 FI4 (cI FI8 ( dI 3 FI 8 I AIEEE 2004 ] A charged particle q is shot towards another charged particle Q, which is fixed, with a speed v. It approaches Q upto a closest distance r and then returns. If q was given a speed 2v, the closest distance of approach would be

q ===-+·································Q

.

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.-r-.
(a) r (b) 2r

(c) rl2

(d)

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13 - ELECTROSTATICS
( Answers at the end of all questions

Page 2

1

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Four charges equal to -Q are placed at the four corners of the square and a charge q