When the atoms in a sample of hydrogen like atoms are in the fourth (n = 4) orbit, how many spectral lines will be emitted in the radiation spectrum of the sample?
4
5
6
9
Three-fourths of the active nuclei present in a radioactive sample decay in 3/4 s. The half-life of the sample is
1 s
½ s
¾ s
3/8 s
Photon of frequency v has a momentum associated with it. If c is the velocity of light, the momentum is
v/c
hvc
hv/c2
hv/c
For a given photo sensitive meterial, there exists a certain minimum cut - off frequency of the incident radiation what is called this frequency?
Minimum frequency
Maximum frequency
Threshold frequency
Power frequency
What is the De Broglie wavelength associated with an electron accelerated throgh a potential difference of 100 volts?
λ = 0.123 nm
λ = 1nm
λ = 0.135 nm
λ = 1.123 nm
Bragg's equation will have no solution, if
λ > 2d
λ < 2d
λ < d
λ = d
Monochromatic light incident on a metal surface emits electrons with kinetic energies from 0 to 2.6 eV. What is the least energy of the incident photon, if the tightly bound electrons needs 4.2 eV to remove?
1.6 eV
Between 1.6 eV and 6.8 eV
6.8 eV
More than 6.8 eV
An electron is accelerated through a potential difference of 1000 volt. Velocity is nearly
3.8 × 107 m s-1
1.9 × 106 m s-1
1.9 × 107 m s-1
5.7 × 107 m s-1
Light of wavelength 4000 angstrom is incident on a sodium surface for which the threshold wavelength of photoelectrons is 5420 angstrom. The work function is
4.58 electron volt
2.31 electron volt
1.14 electron volt
0.57 electron volt
A photon of energy 10.2 eV corresponds to light of wavelength λ0. Due to an electron transition from n = 2 to n = 1 in a hydrogen atom, light of wavelength λ is emitted. If we take into account the recoil of an atom, when a photon is emitted,
λ = λ0
λ < λ0
λ > λ0
The data is not sufficient to reach a conclusion.
