CBSE 2022 · Region 5 · Set 2 · Q5 · 3 marks
An alpha particle is accelerated through a potential difference of $\displaystyle 100$ V. Calculate :(i)The speed acquired by the alpha particle, and(ii)The de-Broglie wavelength associated with it. (Take mass of alpha particle $\displaystyle =6.4 \times 10^{-27} \mathrm{~kg}$ )
An alpha particle is accelerated through a potential difference of $\displaystyle 100$ V. Calculate :
(i)
The speed acquired by the alpha particle, and
(ii)
The de-Broglie wavelength associated with it. (Take mass of alpha particle $\displaystyle =6.4 \times 10^{-27} \mathrm{~kg}$ )
Marking-scheme solution
(i)
$\displaystyle \mathrm{V}=\sqrt{\frac{2 q V}{m}}$
$$\begin{aligned}
& =\sqrt{\frac{$\displaystyle 2$ \times $\displaystyle 2$ \times $\displaystyle 1.6$ \times $\displaystyle 10$^{-$\displaystyle 19$} \times $\displaystyle 100$}{$\displaystyle 6.4$ \times $\displaystyle 10$^{-$\displaystyle 27$}}}
& \quad=$\displaystyle 1$ \times $\displaystyle 10$^{$\displaystyle 5$} \mathrm{~m} / \mathrm{s}
\end{aligned}
$$ii) $\displaystyle \lambda=\frac{h}{p}=\frac{h}{m v}$
$$\begin{aligned}
& =\frac{$\displaystyle 6.63$ \times $\displaystyle 10$^{-$\displaystyle 34$}}{$\displaystyle 6.4$ \times $\displaystyle 10$^{-$\displaystyle 27$} \times $\displaystyle 10$^{$\displaystyle 5$}}
& \lambda=$\displaystyle 10$^{-$\displaystyle 12$} \mathrm{~m}
\end{aligned}
Dual Nature of Radiation and MatterWave Nature of MatterApplyshort_answermedium
More from Dual Nature of Radiation and Matter
- Consider a neutron (mass m ) of kinetic energy E and a photon of the same energy. Let λ n and λ p be the de…2024 · asked 3×
- Assertion: Photoelectric current increases with an increase in intensity of incident radiation, for a given…2024 · asked 3×
- Figure shows the variation of photoelectric current measured in a photo cell circuit as a function of the…2023 · asked 3×
- Atomic spectral emission lines of hydrogen atom are incident on a zinc surface. The lines which can emit…2025 · asked 3×
- A beam of red light and a beam of blue light have equal intensities. Which of the following statements is…2025 · asked 3×
- Assertion: If accelerated electrons are passed through a narrow slit, a diffraction pattern is observed.…2026 · asked 3×
- Assertion: In photoelectric effect, the kinetic energy of the emitted photoelectrons increases with increase…2024 · asked 3×
- The figure shows v m^2 versus 1/(λ) graph for photoelectrons emitted from a surface where v m is the maximum…2023 · asked 3×
CBSE Class 12 Physics past-paper question from the 2022board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.