What will be the momentum, of the electrons accelerated through a potential difference of \(56~\text V?\)
1. \(4.07 \times 10^{-25}~\text{kg}~\text{ms}^{-1 }\)
2. \(4.04 \times 10^{-24}~\text{kg}~\text{ms}^{-1 }\)
3. \(4.07 \times 10^{-24}~\text{kg}~\text{ms}^{-1 }\)
4. \(4.04 \times 10^{-25}~\text{kg}~\text{ms}^{-1 }\)

What is the de-Broglie wavelength of an electron with the kinetic energy of \(120\) eV?
1. \(0.123\) nm
2. \(0.121\) nm
3. \(0.112\) nm
4. \(0.131\) nm

For what kinetic energy of a neutron will the associated de Broglie wavelength be
1.40 x ${10}^{-10}$ m?

1.\(1.1 \times 10^{-2}\ eV\)
2.\(2.1 \times 10^{-2}\ eV\)
3.\(3.3 \times 10^{-2}\ eV\)
4.\(4.2 \times 10^{-2}\ eV\)

What is the de Broglie wavelength of a nitrogen molecule in air at 300 K? Assume that the molecule is moving with the root-mean-square speed of molecules at this temperature. (Atomic mass of nitrogen = 14.0076 u)

1. 0.028 nm
2. 0.031 nm
3. 0.127 nm
4. 0.0139 nm

About \(5\)% of the power of a \(100\) W light bulb is converted to visible radiation. What is the average intensity of visible radiation at a distance of \(1\) m from the bulb?

1. \(0.472\) W/m²
2. \(0.398\) W/m²
3. \(0.323\) W/m²
4. \(0.401\) W/m²

What is the de-Broglie wavelength of a bullet of mass \(0.040\) kg traveling at the speed of \(1.0\) km/s?

 An electron and a photon each have a wavelength of 1.00 nm. The momentum of the electron will be:

1. Greater than photon.
2. Equal to the photon.
3. Less than photon.
4. None of these.
 

The work function of cesium metal is \(2.14\) eV. When light of frequency \(6\times10^{14}\) Hz is incident on the metal surface, photoemission of electrons occurs. What is the stopping potential of the metal?

The photoelectric cut-off voltage in a certain experiment is \(1.5~\text{V}\). What is the maximum kinetic energy of photoelectrons emitted?

Monochromatic light of wavelength \(632.8~\text{nm}\) is produced by a helium-neon laser. The power emitted is \(9.42~\text{mW}\). The energy of each photon in the light beam is:
1. \(4.801 \times 10^{-19}~\text{J}\)
2. \(2.121 \times 10^{-19}~\text{J}\)
3. \(5.043 \times 10^{-19}~\text{J}\)
4. \(3.141 \times 10^{-19}~\text{J}\)