Electrostatics Question 201

Question: Two copper balls, each weighing 10g are kept in air 10 cm apart. If one electron from every 106 atoms is transferred from one ball to the other, the coulomb force between them is (atomic weight of copper is 63.5) [KCET 2002]

Options:

A) 2.0×1010 N

B) 2.0×104 N

C) 2.0×108 N

D) 2.0×106 N

Show Answer

Answer:

Correct Answer: C

Solution:

Number of atoms in given mass

=1063.5×6.02×1023 = 9.48 x 1022

Transfer of electron between balls

=9.48×1022106 = 9.48 x 1016

Hence magnitude of charge gained by each ball. Q = 9.48 x 1016 x 1.6 x 10^19 = 0.015 C

Force of attraction between the balls F=9×109×(0.015)2(0.1)2=2×108N.



NCERT Chapter Video Solution

Dual Pane