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Physics · WORK, ENERGY AND POWER
हिन्दीAn electron has a kinetic energy of \( 10\text{ keV} \) and a proton has a kinetic energy of \( 100\text{ keV} \). Taking the mass of an electron as \( 9.11 \times 10^{-31}\text{ kg} \) and proton mass as \( 1.67 \times 10^{-27}\text{ kg} \), the ratio of the speed of the electron to that of the proton is approximately:
Correct answer · Option B
\( 13.5:1 \)
Explanation
\( v = \sqrt{2K/m} \implies \frac{v_e}{v_p} = \sqrt{\frac{K_e}{K_p} \times \frac{m_p}{m_e}} = \sqrt{\frac{10}{100} \times \frac{1.67 \times 10^{-27}}{9.11 \times 10^{-31}}} = \sqrt{0.1 \times 1833} = \sqrt{183.3} \approx 13.54 \).
