Question
A proton and an a particle are accelerated through the same potential difference. Which one of the two has (i) greater de-Broglie wavelength, and (ii) less kinetic energy? Justify your answer.
✓
Answer
- $\lambda =\frac{\text{h}}{\text{p}} =\frac{\text{h}}{\sqrt{2\text{mqV}}}$
$\lambda_{proton} > \lambda_{\propto} - particle$
(Also, $\frac{\lambda_{proton}}{\lambda_{\alpha}} =2\sqrt{2}(\text{ or }\sqrt{8} ) $
- K.E. = q V
$(\text{K.}\text{E} )_{proton} < (\text{K.}\text{E} )_{\alpha - particle}$
$\text{Also},\frac{(\text{K.E.})\propto}{(\text{K.E.})_{\rho}} = 2 ) $.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
Consider the situation shown in figure. The switch is closed at $t = 0$ when the capacitors are uncharged. Find the charge on the capacitor $C_1$ as a function of time $t$.
→What is the importance of radial magnetic field in a moving coil galvanometer ?
Why are small pieces of paper attracted by a dry comb rubbed against dry hair?
A barometer is constructed with its tube having radius $1.0\ mm$. Assume that the surface of mercury in the tube is spherical in shape. If the atmospheric pressure is equal to $76\ cm$ of mercury, what will be the height raised in the barometer tube. The contact angle of mercury with glass $= 135^\circ$ and surface tension of mercury $= 0.465N/m$. Density of mercury $= 13600\ kg/m^3$.
→A car weighing $1400\ kg$ is moving at a speed of $54\ km/h$ up a hill when the motor stops. If it is just able to reach the destination which is at a height of $10m$ above the point, calculate the work done against friction $($negative of the work done by the friction$).$
→Draw a ray diagram of a reflecting type telescope. State two advantages of this telescope over a refracting telescope.
In some old texts it is mentioned that $4\pi$ lines of force originate from each unit positive charge. Comment on the statement in view of the fact that $4\pi$ is not an integer.
→State the Oersted's observation.
Suppose the energy liberated in the recombination of a hole-electron pair is converted into electromagnetic radiation. If the maximum wavelength emitted is 820nm, what is the band gap?
Write any three characteristics, a ferromagnetic substance should possess if it is to be used to make a permanent magnet. Give one example of such a material.