STATEMENT – 1
When ultraviolet light is incident on a photocell, its stopping potential is V0 and the maximum kinetic energy of the photoelectrons is Kmax. When the ultraviolet light is replaced by X–rays, both V0 and Kmax increase.
STATEMENT – 2
Photoelectrons are emitted with speeds ranging from zero to a maximum value because of the range of frequencies present in the incident light.
Statement – 1 is True, Statement – 2 is False.
Statement – 1 is True, Statement – 2 is True; Statement – 2 is a correct explanation for Statement – 1.
Statement – 1 is True, Statement – 2 is True; Statement – 2 is not the correct explanation for Statement – 1.
Statement – 1 is True, Statement – 2 is True; Statement – 2 is not the correct explanation for Statement – 1.
A nucleus of mass M + Δm is at rest and decays into two daughter nuclei of equal mass M/2 each. The speed of light is c.
The binding energy per nucleon for the parent nucleus is E1 and that for the daughter nuclei is E2. Then
E1 = 2E2
E2 = 2E1
E1 > E2
E1 > E2
A nucleus of mass M + Δm is at rest and decays into two daughter nuclei of equal mass M/2 each. Speed of light is c.
The speed of daughter nuclei is
A radioactive nucleus (initial mass number A and atomic number Z) emits 3 α–particles and 2 positions. The ratio of number of neutrons to that of protons in the final nucleus will be
If a source of power 4kW produces 1020 photons/second, the radiation belongs to a part of the spectrum called
X -rays
ultraviolet rays
microwaves
microwaves
The potential energy function for the force between two atoms in a diatomic molecule is approximately given by where a and b are constants and x is the distance between the atoms. If the dissociation energy of the molecule is D = [U(x = ∞) – Uat equilibrium], D is
b2/2a
b2/12a
b2/4a
b2/4a
The speed of light in the medium is
maximum on the axis of the beam
minimum on the axis of the beam
the same everywhere in the beam
the same everywhere in the beam
An initially parallel cylindrical beam travels in a medium of refractive index μ(I) = μ0 +μ2I , where μ0 and μ2 are positive constants and I is the intensity of the light beam. The intensity of the beam is decreasing with increasing radius.
As the beam enters the medium, it will
travel as a cylindrical beam
diverge
converge
converge
An initially parallel cylindrical beam travels in a medium of refractive index μ(I) = μ0 +μ2I , where μ0 and μ2 are positive constants and I is the intensity of the light beam. The intensity of the beam is decreasing with increasing radius.
The initial shape of the wavefront of the beam is
convex
concave
convex near the axis and concave near the periphery
convex near the axis and concave near the periphery
D.
convex near the axis and concave near the periphery
For a parallel cylindrical beam, wave length will be planar.