Light of wavelength 4000 Å falls on a photosensitive metal and a negative 2V potential stops the emitted electrons.
The work function of the material (in eV) is approximately
1. 1.1
2. 2.0
3. 2.2
4. 3.1
1. | \(\frac{m_1}{m_2} \) | 2. | \(\frac{m_2}{m_1} \) |
3. | \(1 \) | 4. | \(\sqrt{\frac{\mathrm{m}_2}{\mathrm{~m}_1}}\) |
The de-Broglie wavelength of a body of mass 1 kg moving with a velocity of 2000 m/s is
1.
2.
3.
4. None of these
An electron at rest is acceleration by a potential difference of 600V. The de-Broglie wavelength associated with the electron is:
1.
2.
3.
4.
When the light of wavelength is made to fall on metal in a photoelectric experiment, the maximum kinetic energy of emitted electrons is found to be 2.5eV. The work function of the metal is:
1. 2.5eV
2. 3.1eV
3. 0.9eV
4. 1.5eV
When the light of wavelength is used in a photoelectric experiment, the maximum kinetic energy of emitted electrons is found to be K. What will the maximum kinetic energy of the photoelectrons when the light of wavelength is used instead of :
1. Zero
2. Non zero but less than 2 K
3. 2K
4. More than 2K
Electrons used in an electron microscope are accelerated by a voltage of 25 kV. If the accelerating voltage is reduced to 6.25 kV, the resolving power of the microscope would:
1. Increase to 4 time
2. Increases to 2 times
3. Decrease to half
4. Decrease to 1/4th
In a photoelectric experiment using a metal of work function 1.8 eV, if the maximum kinetic energy of emitted electrons is 1.5eV, then the corresponding value to stopping potential is:
1. 1.8V
2. 3.3V
3. 0.3V
4. 1.5V
Monochromatic radiation emitted when an electron in a hydrogen atom jumps from the first excited state to the ground state irradiates a photosensitive material. The stopping potential is found to be 4V. The threshold wavelength of the material is