CBSE
Multiple Choice QuestionsA leaf which contains only green pigments is illuminated by a laser light of wavelength 0.6328 μm. It would appear to be
brown
black
red
green
If an electron and a photon propagate in the form of waves having the same wavelength, it implies that they have the same
energy
momentum
velocity
angular momentum
Assertion: The energy (E) and momentum (p) of a phoon are related by p = E/c.
Reason: the photon behaves like a particle.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false
A photon of energy 4 eV is incident on a metal surface whose work function is 2 eV. The minimum reverse potential to be applied for stopping the emission of electrons is
2 V
4 V
6 V
8 V
Characteristic X-rays are produced due to
transfer of momentum in collision of electrons with target atoms
transition of electron from higher to lower electrons orbits in an atom
heating of the target
transfer of energy in collision of electrons with atoms in the target
We wish to see inside an atom. Assuming the atom to have a diameter of 100 pm, this means that one must be able to resolve a width of say 10 pm. If an electron microscope is used, the minimum electron energy required is about
1.5 keV
15 keV
150 keV
1.5 keV
Assertion: A red object appears dark in the yellow light.
Reason: The red colour is scattered less.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false
Assertion: A tube light emits white light.
Reason: Emission of light in a tube takes place at a very high temperature.
if both assertion and reason are true and the reason is the correct explanation of the assertion
if both assertion and reason are true and the reason is not the correct explanation of the assertion
if assertion is true but reason is false
if both assertion and reason are false statements
Assertion: Photoelectric effect demonstrates the wave nature of light.
Reason: The number of photoelectrons is proportional to the frequency of light
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false
The speed of an electron having a wavelength of 10-10 m is
7.25 × 106 m/s
5.25 × 106 m/s
6.26 × 106 m/s
4.24 × 106 m/s
