Single Choice

The ratio of the electrostatic force of attraction to the gravitational force between the proton and electron of the hydrogen atom is of the order of

A$$10^{39}$$
Correct Answer
B$$10^{-39}$$
C$$10^{8}$$
D$$10^{-8}$$

Solution

Electrostatic force of attraction $$=\dfrac {k q_1 q_2}{r^2}$$

$$=\dfrac {9\times 10^9\times (1\cdot 6\times 10^{-19})^2}{r^2}$$
Gravitational force of attraction $$=\dfrac {Gm_em_p}{r^2}$$

$$=\dfrac {(6\cdot 67\times 10^{-11})(9\cdot 1\times 10^{-31})(1\cdot 67\times 10^{-27})}{r^2}$$

$$Ratio \dfrac {F_e}{F_g}=\dfrac {9\times 10^9\times (1\cdot 6\times 10^{-19})^2}{(6\cdot 67\times 10^{-11})(9\cdot 1\times 10^{-31})(1\cdot 67\times 10^{-27})}$$

$$=\dfrac {23\cdot 04\times 10^{-29}}{101\cdot 36\times 10^{-69}}$$

$$=2\cdot 27\times 10^{39}$$

SIMILAR QUESTIONS

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