Physics
GATE PH format:nat PYQs
Build your understanding with focused practice from past exam papers.
Questions 71–80 of 182. Imported answers require independent review unless marked reviewed.
Question 21
Open questionPHNAT1 markNeeds review
Three non-interacting bosonic particles of mass
each, are in a one-dimensional infinite potential well of width
. The energy of the third excited state of the system is
. The value of
(in integer) is ______.Log in to check the answer
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Open questionPHNAT1 markNeeds review
The spacing between two consecutive S-branch lines of the rotational Raman spectra of hydrogen gas is 243.2 cm
. After excitation with a laser of wavelength 514.5 nm, the Stoke’s line appeared at 1761.1 cm
for a particular energy level. The wavenumber (rounded off to the nearest integer), in cm
, at which Stoke’s line will appear for the next higher energy level is ______.Log in to check the answer
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Open questionPHNAT1 markNeeds review
The transition line, as shown in the figure, arises between
and
states without any external magnetic field. The number of lines that will appear in the presence of a weak magnetic field (in integer) is ______. 
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Consider the atomic system as shown in the figure, where the Einstein A coefficients for spontaneous emission for the levels are
and
. If
atoms/cm
are excited from level 0 to level 2 and a steady state population in level 2 is achieved, then the steady state population at level 1 will be
cm
. The value of
(in integer) is ______. 
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Open questionPHNAT1 markNeeds review
If
and
are constant vectors,
and
are generalized positions and conjugate momenta, respectively, then for the transformation
and
to be canonical, the value of
(in integer) is ______.Log in to check the answer
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Open questionPHNAT2 marksNeeds review
A linear charged particle accelerator is driven by an alternating voltage source operating at 10 MHz. Assume that it is used to accelerate electrons. After a few drift-tubes, the electrons attain a velocity 2.9 × 10^8 m s⁻¹. The minimum length of each drift-tube, in m, to accelerate the electrons further (rounded off to one decimal place) is _____.
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Open questionPHNAT2 marksNeeds review
The Coulomb energy component in the binding energy of a nucleus is 18.432 MeV. If the radius of the uniform and spherical charge distribution in the nucleus is 3 fm, the corresponding atomic number (rounded off to the nearest integer) is _____.
(Given:
MeV fm)Log in to check the answer
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Open questionPHNAT2 marksNeeds review
For a two-nucleon system in spin singlet state, the spin is represented through the Pauli matrices
for particles 1 and 2, respectively.
The value of
(in integer) is _____.Log in to check the answer
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Open questionPHNAT2 marksNeeds review
A contour integral is defined as
where
is a positive integer and
is the closed contour, as shown in the figure, consisting of the line from −100 to 100 and the semicircle traversed in the counter-clockwise sense.The value of
(in integer) is _____. 
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Open questionPHNAT2 marksNeeds review
The normalized radial wave function of the second excited state of hydrogen atom is
where
is the Bohr radius and
is the distance from the center of the atom. The distance at which the electron is most likely to be found is
. The value of
(in integer) is _____.Log in to check the answer
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