IIT JEE , AIEEE Forum - Physics , Electricity - Electrostatics-Answer not matching

payal_bon

Electrostatics-Answer not matching

payal_bon

Two insulating small spheres are rubbed against each other and placed 1 cm apart> If they attract each other with a force of 0.1 N how many electrons were transferred from one sphere to anotherduring rubbing?

Ans: 2*10^11

If answer matches then please post the solution.

shub

both the spheres will acquire equal charges....let it be q

F = 1/4 $\pi\epsilon$ * q^2/r^2

.1 = 9*10^9 * q^2/10^ -4

on solving q = 1/ 3* 10^ 7

charge on 1 electron = 1.6 * 10 ^ -19 C

no of electrons to make up 1? 3 * 10 ^ 7 C =

1/300*10^7*1.6*10^ -19 (all are in denominator)

on solving u get the answer.....

mukulaish

my answer is comin 2*10(raised 2 the power 11)

solvin the coulomb's law expression v get 1= 3.3*10(raied 2 the power -8)
now 1 electron has charge 1.6*10(raied 2 the power -19) C
so 3.3*10(raised 2 the power -7) C charge will b hold by 2*10(raised 2 the power 11) electrons.....

lemme knw whether u got it or not..

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