Question

A hypothetical sub-atomic particle has a mass $\frac{1}{9.1}$ times of an electron and a charge double than that of a proton. Calculate the charge to mass ratio.

• A. $3.2\times {10}^{12}Ck{g}^{-1}$
• B. $1.2\times {10}^{12}Ck{g}^{-1}$
• C. $1.2\times {10}^{10}Ck{g}^{-1}$
• D. $3.2\times {10}^{10}Ck{g}^{-1}$

Answer 1

The correct option is A $3.2\times {10}^{12}Ck{g}^{-1}$

Given,
$\text{Mass of the particle}=\frac{\text{mass of electron}\left(m_e\right)}{9.1}=\frac{m_e}{9.1}$

$\text{Charge of the particle}=+2e$

$\therefore \text{Charge to mass ratio}=\frac{2e}{\frac{m_e}{9.1}}=\frac{9.1\times 2\times 1.6\times {10}^{-19}}{9.1\times {10}^{-31}}=3.2\times {10}^{12}Ck{g}^{-1}$