Question

Calculate the ratio of electrostatic to gravitational force between two electrons placed at certain distance in air. Given that `m_(e)= 9.1xx10^(-31) kg,e= 1.6xx10^(-19)C` and `G=6.6xx10^(-11)Nm^(-2)`.
A. `8.4xx10^(42)`
B. `3.2xx10^(41)`
C. `4.2xx10^(42)`
D. `1.2xx10^(42)`

Answer 1

Correct Answer - c
`(F_("elec"))/(F_(graw))= 1/(4piepsilon_(0))*(exxe)/(r^(2))//G(m_(e)xxm_(e))/(r^(2))=1/(4piepsilon_(0))*(e_(2))/(Gm_(e)^(2))`
Putting `G= 6.6xx10^(-11)Nm^(-2)`,
`m_( e)= 9.1xx10^(-31) kg` and `e= 1.6xx10^(-19)C`, we get
`(F_("elec"))/(F_(graw))= 4.2xx10^(42)`.