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The ratio of gravitational force and electrostatic repulsive force between two electrons is approximately (gravitational constant $=6.7 \times 10^{-11} \,Nm ^2 / kg ^2$, mass of an electron $=9.1 \times 10^{-31} \,kg$, charge on an electron $=1.6 \times 10^{-19} C$ )
$24 \times 10^{-24}$
$24 \times 10^{-36}$
$24 \times 10^{-44}$
$24 \times 10^{-54}$
Solution
(c)
Given, gravitational constant $=6.7 \times 10^{-11} \,Nm ^{-2} / kg ^2$
Mass of an electron $=9.1 \times 10^{-31} \,kg$
Charge of an electron $=1.6 \times 10^{-19} \,C$
Gravitational force, $F_G=\frac{G n_1 m_2}{r^2}$
$=\frac{6.7 \times 10^{-11} \times\left(9.1 \times 10^{-31}\right)^2}{r^2}$
Electrostatic repulsive force,
$F_E =\frac{K q_1 q_2}{r^2}$
$=\frac{9 \times 10^9 \times\left(1.6 \times 10^{-19}\right)^2}{r^2}$
$\therefore \frac{F_G}{F_E}=\frac{6.7 \times 10^{-11} \times\left(9.1 \times 10^{-31}\right)^2}{9 \times 10^9 \times\left(1.6 \times 10^{-19}\right)^2}$
$=24 \times 10^{-44}$