The electrons of potassium were not ejected when red light fall on a piece of potassium metal. The electrons will be ejected when
Intensity of light is increased
Wave length of light is increased
Wave number of light is increased
Amplitude of light is increased
The fundamental particle which is responsible for keeping the nucleons together is
Electron
Proton
Positron
Meson
What is the wave length of a radio wave having frequency 2.5 × 105 Hz ?
1.2 × 103m
1.2 × 10-3m
8.33 × 102m
None of these
How many number of spherical nodes will be in 4p orbitals ?
1
3
2
Zero
What is the ratio between the energy of a photon of 1500 Ao wave length radiation to that of 3000 Ao wave length radiation ?
1/4
1/2
4
The correct set of quantum numbers for the unpaired electron of chlorine atom is
n = 3, l = 1, ml = 1
n = 2, l = 1, ml = 0
If the speed of electron in the Bohr's first orbit of hydrogen atom is 'V' ,then the speed of the electron in the fourth orbit is
4V
V/4
V/2
V/16
The uncertainity in the momentum of an electron is 2.0 × 10-5kgms-1. The uncertanity in its position will be
5.27 × 10-30m
1.05 × 10-26m
2.638 × 10-30m
3.313 × 10-28m
The quantum number not obtained from Schrodinger wave equation is
s
l
m
n
The spectral line obtained when an electron jumps from n = b to n = 4 energy level belongs to
Paschen series
Brackett series
Lyman series
none of these
