The current conduction in a discharge tube is due to:
1. electrons only
2. +ve ions and –ve ions
3. –ve ions and electrons
4. +ve ions and electrons
If a light of amplitude A and wavelength λ is incident on a metallic surface, then the saturation current flow is proportional to (assume cut-off wavelength = ):
1.
2.
3.
4.
1. | less than \(0.5 ~\text{eV}\). |
2. | \(0.5 ~\text{eV}\). |
3. | greater than \(0.5 ~\text{eV}\). |
4. | the photoelectric effect does not occur. |
The total energy of an electron is \(3.555~\text{MeV}\). Its kinetic energy will be:
1. \(3.545~\text{MeV}\)
2. \(3.045~\text{MeV}\)
3. \(3.5~\text{MeV}\)
4. none of the above
The value of Planck's constant is:
1. | \(6.63\times 10^{-34}~\text{J/s}\) | 2. | \(6.63\times 10^{-34}~\text{kg-}\text{m}^2\text{/s}\) |
3. | \(6.63\times 10^{-34}~\text{kg-}\text{m}^2\) | 4. | \(6.63\times 10^{-34}~\text{J-s}^2\) |
If particles are moving with the same velocity, then the de-Broglie wavelength is maximum for:
1. proton
2. \(\alpha\text-\)particle
3. neutron
4. \(\beta\text-\)particle
When ultraviolet rays strike a metal plate, the photoelectric effect does not occur. It occurs by the incidence of:
1. Infrared rays
2. X-rays
3. Radio wave
4. Lightwave
Which of the following is not the property of cathode rays:
1. | it produces a heating effect. |
2. | it does not deflect in the electric field. |
3. | it casts a shadow. |
4. | it produces fluorescence. |
Which one among the following shows the particle nature of light?
1. | Photoelectric effect | 2. | Interference |
3. | Refraction | 4. | Polarisation |