Two copper spheres A and B have equal radii. If sphere A has 100 electrons and sphere B has 400 protons then what will be the electric charge on each of them when they are brought in contact and separated ?

Options

A. `4.8 xx 10^(-17)` C
B. `2.4 xx 10^(-17)` C
C. `1.6 xx 10^(-17)`
D. `6.4 xx 10^(-17)` C

Answer

B

Explanation

Total charge when they are in contact,
`Q = n_(1)(-e) + n_(2)(e)`
`=-100e + 400e = 300e`
`=300 xx 1.6 xx 10^(-19) C = 4.8 xx 10^(-17) C`
Equal charge will be distributed when they are separated.
`therefore` Total charge on each sphere `=(4.8 xx 10^(-17))/2`
`=2.4 xx 10^(-17)` C