What will be the percentage change in the de-Broglie wavelength of the particle if the kinetic energy of the particle is increased to 16 times its previous value?
1. 25
2. 75
3. 60
4. 50
The wavelength \(\lambda_{e}\) of an electron and \(\lambda_{p}\) of a photon of the same energy E are related as:
1.
2.
3.
4.
An \(\alpha -\) particle moves in a circular path of radius 0.83 cm in the presence of a magnetic field of \(0.25 \mathrm{~Wb} / \mathrm{m}^2\). The de-Broglie wavelength associated with the particle will be:
1. | \(1~\mathring {\text{A}}\) | 2. | \(0.1~\mathring {\text{A}}\) |
3. | \(10~\mathring {\text{A}}\) | 4. | \(0.01~\mathring {\text{A}}\) |
If the momentum of an electron is changed by p, then the de-Broglie wavelength associated with it changes by 0.5%. What is the initial momentum of the electron?
1. 200p
2. 400p
3.
4. 100p
The potential difference that must be applied to stop the fastest photoelectrons emitted by a nickel surface having a work function of 5.01 eV when ultraviolet light of 200 nm falls on it is:
1. | 2.4 V | 2. | - 1.2 V |
3. | - 2.4 V | 4. | 1.2 V |
When monochromatic radiation of intensity I falls on a metal surface, the number of photoelectrons and their maximum kinetic energy are N and T respectively. If the intensity of radiation is 2I what is the number of emitted electrons and their maximum kinetic energy?
1. | N and 2T | 2. | 2N and T |
3. | 2N and 2T | 4. | N and T |
A helium-neon laser produces monochromatic light of a wavelength of 667 nm. The power emitted is 9 mW. The average number of photons arriving per second on average at a target irradiated by this beam is:
1.
2.
3.
4.
A particle of mass 1 mg has the same wavelength as an electron moving with a velocity of . What will be the velocity of the particle? (mass of electrons = 9 . 1 × 10- 31 kg )
1. | \(2.7 \times 10^{-18} \mathrm{~ms}^{-1}\) |
2. | \(9 \times 10^{-2} \mathrm{~ms}^{-1}\) |
3. | \(3 \times 10^{-31} \mathrm{~ms}^{-1}\) |
4. | \(2.7 \times 10^{-21} \mathrm{~ms}^{-1}\) |
Waves are associated with matter only:
1. | When it is stationary. |
2. | When it is in motion with the velocity of light only. |
3. | When it is in motion with any velocity. |
4. | None of the above. |
A particle which has zero rest mass and non-zero energy and momentum must travel with a speed:
1. | Equal to c, the speed of light in vacuum. |
2. | Greater than c. |
3. | Less than c. |
4. | Tending to infinity. |