Order of e/m ratio of proton, α-particle and electron is

Options

(a) e>p>α
(b) p>α>e
(c) e>α>p
(d) None of these

Correct Answer:

e>p>α

Explanation:

For electron (e / mₑ) = 1.6 × 10⁻¹⁹ / 9 × 10⁻³¹ = 1.75 × 10¹¹ C kg⁻¹

For proton [e / m(p)] = 1.6 × 10⁻¹⁹ / 1.67 × 10⁻²⁷ = 9.58 × 10⁷ C kg⁻¹

For α-particle [e / m(α)] = 2 × 1.6 × 10⁻¹⁹ / 6.6 × 10⁻²⁷ = 4.84 × 10⁷ C kg⁻¹

Hence the ratio (e/m) for e > p > α