A double slit experiment is performed with light of wavelength 500 nm. A thin film of thickness 2 μm and refractive index 1.5 is introduced in the path of the upper beam. The location of central maximum will
remain unshifted
shift downward by nearly two fringes
shift upward by nearly two fringes
shift downward by 10 fringes
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
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
In an experiment to find the focal length of a concave mirror a graph is drawn between the magnitudes of u and v. The graph looks like
Nuclear fusion is possible
only between light nuclei
only between heavy nuclei
between both light and heavy nuclei
only between nuclei which are stable against β-decay
Radioactive nuclei that are injected into a patient collect at certain sites within its body, undergoing radioactive decay and emitting electromagnetic radiation. These radiations can then be recorded by a detector. This procedure provides an important diagnostic tool called
gamma camera
CAT scan
radiotracer technique
gamma ray spectrosccopy
In a material medium, when a positron meets an electron both the particles annihilate leading to the emission of two gamma ray photons. This process forms the basis of an important diagnostic procedure called
MRI
PET
CAT
SPECT
B.
PET
Positron emission tomography (PET) is a nuclear medicine medical imaging technique which produces a three dimensional image or map of functional process m the body. A short lived radioactive tracer isotope which decays by emitting a positron chemically incorporated into a metabolically active molecule, is injected into the living subject (usually into blood circulation). There is a waiting period after which the short-lived isotope decays, emitting a positron. After travelling up to a few millimetres the positron annihilates with an electron, producing a pair of annihilation photons (similar to gamma rays) moving in opposite directions.
An astronaut is looking down on earth's surface from a space shuttle at an altitude of 400 km.
Assuming that the astronaut's pupil diameter is 5 mm and the wavelength of visible light is 500 nm, the astronaut will be able to resolve linear objects of the size about
0.5 m
5 m
50 m
500 m
In the following common emitter configuration an npn transistor with current gain β = 100 is used. The output voltage of the amplifier will be
10 mV
0.1 mV
1.0 mV
10 V
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