If alpha particle, proton and electron move with the same momentum, then their respective de-Broglie wavelengths λα, λp, λe are related
λα = λp = λe
λα < λp < λe
λα > λp > λe
λp > λe > λα
The velocity of a moving galaxy is 300 kms-1 and the apparent change in wavelength of a spectral line emitted from the galaxy is observed as 0.5 nm. Then, the actual wavelength of the spectral line is
3000
5000
6000
4500
The temperature at which protons in proton gas would have enough energy to overcome Coulomb barrier of 4.14 x 10-14 J is (Boltzmann constant = 1.38 x 10-23 JK-1)
2 × 109 K
109 K
6 × 109 K
3 × 109 K
The surface area ofa black body is 5 x 10-4 m2 and its temperature is 727°C. The energy radiated by it per minute is (σ = 5.67 × 10-8 J/m2 s-k4)
1.7 × 103 J
2.5 × 102 J
8 × 103 J
3 × 104 J
The ratio of the de-Broglie wavelength of an α-particle and a proton of same kinetic energy is
1 : 2
1 : 1
4 : 1
A black body has maximum wavelength λm at 2000 K. Its corresponding wavelength at 3000 K will be
Band spectrum is also called
molecular spectrum
atomic spectrum
flash spectrum
line absorption spectrum
A.
molecular spectrum
Band spectrum is also called as molecular spectrum.
The ionization potential of hydrogen is 13.6 V. The energy required to remove an electron from the second orbit of hydrogen is
3.4 eV
6.8 eV
13.6 eV
1.51 eV
As the electron in Bohr orbit of hydrogen atom passes from state n = 2 to n= 1, the kinetic energy K and potential energy U change as
K two-fold, U four-fold
K four-fold, U two-fold
K four-fold, U also four-fold
K two-fold, U also two-fold
Let the potential energy of hydrogen atom in the ground state be regarded as zero. Then its potential energy in the first excited state will be
20.4 eV
13.6 eV
10.2 eV
6.8 eV