For a 3D free electron gas, the electron density n and the Fermi energy E_{F}, are related as
The tight binding energy dispersion relation for electrons in 1D array of a toms having lattice constant a and total length l is E = E_{0} + γ cosh (ka) . where E_{0}, γ are constants and k is wave vector. Which graph best represents the variation of effective mass with energy.
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The magnetization (M) of some hypothetical substance in magnetic field (H) is given by
M (H) = C In^{2}(H + H_{0}), H > l  H_{0}
where H_{0} and C are positive and negative constants respectively. In what category should tliis substance be put
The temperature at which the probability that an energy state with an energy 0.2 e V above the fenni level will be occupied by an electron is 10 %
The dispersion relation of phonons in a solid is given by
Tlie velocity of phonons at large wavelength is related to wave number k as
Consider a crystal with basecenteredcubic lattice with positions of basis atoms at (0, 0, 0) and
The lattice plane for which there is no diffraction peak is
In nearly free election model, the wavefimctions at the Biillonin zone boimclaiy are and , normalized over unit length of line. If potential energy ofan electron in the crystal at point x is V (x) = V_{0} [1  cos (2πx)] . the first order energy gap between two standing waves is
Apdoped semiconductor slab carries a current I = 150 mA in a magnetic field 0.3 T as shown. Voltage differences V_{x} and V_{y} are 2.5 mV and 0.3 mV, respectively. The mobility of majority charge earners is 0.8 m^{2} V^{1} sec^{1}. The current density in mA/m^{2} is
Distance of a point inside a superconductor from the surface, at which the magnetic field is twothird of its value at the surface, in terms of London penetration depth (λ) is
Inteiplanar distance of a plane passing through points (0,0,1), (1,0,0) and in a crystal with lattice constant 2Å is _________ Å. (Upto two decim al places)
Critical magnetic fields of a superconductor at 2K and 6K is 13.5 mA /m and 4.5 mA /m respectively. The transition temperature of the superconductor is _________ K.
[Upto two decimal places]
Consider a semiempirical mass formula of the form
M = 939.6(A  Z) + 938.8Z  14.0A + 13.0 A^{2/3 }+ 0.583Z (Z  1) A^{1/3} +19.3(A  2Z)^{2 }A^{1 }±33.5A^{3/4}
Hence the most stable isobar is
Neutron lias 11011zero magnetic moment confirm that
According to closedshell nucleus model parity of
^{41}C_{a} has a neutron outside closed shell in ^{1 }f_{7/2}. It’s nuclear magnetic momentum is equal to
As one moves along the line of stability from ^{56}Fe to U^{235} nucleus the binding energy per nucleon decreases from 8 MeV to 7.6 MeV Tliis trend is mainly due to the
Two particles He^{+} and Li^{+} are projected in a circular orbit of same radius perpendicular to a given magnetic field
The reaction strong interaction is not possible because
The life time of a free neutron to decay into a proton, an election and an antineutrino is approximately
Consider the strong interaction process
the unknown particle X may be
The binding energy of the neon isotopes is 160.65 Mev. thus, its atomic mass in atomic unit u, would be
Neutron can be expressed in terms of quark
There is a stream of neutrons with a speed 2.5 x 10^{3} m/s. If half life of neutrons is 700 seconds, the fractions of neutrons that will decay before they travel a distance 10m.
(given mass of neutrons = 1.675 x 10^{27}kg)
baryon has the following properties Q = 1, S = 2 & B = 1, the quark content is
The quark content of ∑^{+}, k^{}, π^{} and p is indicated
in die process π^{} + p → k^{} + ∑^{+}
Considering strong interactions only, which of die following is true?
The conservation law violated by die reaction p → π^{0 }+ e^{+} is conservation of
The wavelength of one of the visible lines in the spectrum of the hyclrogen atom is approximately 6560 Å. It is known that this corresponds to a transition between the states with the principal quantum numbers n = 2 and n = 3. Hie frequency corresponding to the transition from die first excited state to die ground state is_______ x 10^{15}Hz.
(Upto two decimal places)
A sample of certain element is placed in a 0.3 Tesla magnetic field and suitably excited. If the wavelength corresponding to the transition ^{1}P → ^{1}S is 450 nm. then the separation in the Zeeman spectral lines is equal to _______ x 10^{12} meter.
(Upto two decim al places)
Xray spectrum o f a cobalt target (Z = 27) contains strong K_{α} line of wavelength 0.1785 nm and a weak line having wavelength of 0.1537 nm due to an impurity. The atomic number of impurity element is_______.
The number of spectroscopic terms resulting from the LS coupling of a 3p electron and a 4p electron is ______.
The term symbol for ground state of ^{17}Cl and ^{20}Ca are respectively.
The total magnetic moment in Bohr magneton μ_{B} of an atom in the ^{3}p_{2} state is_______ μ_{B}.
(Upto two decimal places)
All atomic spectral line is observed to split into six components due to Zeem an shift. If the upper state of the Unseen atom is ^{3 }P_{1}, then the lower state will be
The transition j = 3 to J = 4 in HCl molecule is associated with radiation of 86 cm^{1}. Using rigid rotator approximation, the moment of inertia of the molecule is ________ x 10^{47} kgm^{2}.
(Upto two decimal places)
If the time taken by an election to traverse the first orbit in hydrogen atom is T, then the time taken by an election to traverse the second orbit in lithium (Li^{2+}) ion is
March the following and choose die correct option.
In vibrational spectra, the fundamental band of H^{1}Cl^{35} occurs at 2886 cm^{1}. The frequency of the corresponding mode of the H^{3}Cl^{35} is ______ cm^{1} [In terms of integer]
The fundamental band for CO is centered at 2143 cm^{1} and the first overtone at 4259.7 cm^{1}. The value of anhannonicity constant is ________.
(Upto three decimal places)
Amongst the following transitions, which one is forbidden according to electric dipole transition?
If we consider a diatomic molecule as a nonrigid rotator, then the wave number for the transition from J = 1 to J = 2 is given by (where B is rotational constant and D is centrifugal distaition constant)
A substance shows a Raman line at 4567 Å when the exciting line 4358 Å is used. The wavelength of the stokes line for the 4358 Å is used. The wavelength of the stokes line for the same substance when exciting line 4047 Å is used is
The ratio of population of the upper and lower states in a HeNe laser that produces light of wavelnegth 6328Å at 27°C is
Which of the following nuclei will not showNMR spectrum ?
If Laser line width occurs at 10 Hz. then the coherence length is
The microwave spectrum of H^{1}Br^{79} consist of a series of lines spaced 14 cm^{1} apart. The intemuclear distance of the molecule is ______ Å (UDto two decimal places)
[Given : h = 6.63 x 10^{34} Js, c = 3 x 10^{8} m/s. N_{A} = 6.023 x 10^{23} mol^{1}]
An x ray machine operates at a potential of 5000 V. The minimum possible value of wavelength present in the radiations is
A metal with facecenteredcubic (FCC) structure shows the first diffraction peak at a Bragg angle of θ = 30°. Tlie wavelengtii of Xray used is 2Å. The volume of the primitive cell of the metal is _____ [in Å^{3}],
(upto two decimal places)
Consider the gamma transition in nucleus:
Orbital motion of an election precesses in a magnetic field. The precessional frequency in a magnetic field Unseen which makes θ angle with the plane of orbit is
Xray beam of intensity I_{º} passes through an absorption plate of thickness d. If absorption coefficient of material of plate is μ, the correct statement regarding the transmitted intensity I of Xray is :
The graph that represents the interaction o f the proton and neutron is
Magnetic moment of an electron moving circularly around nucleus in Hlike atom in an orbit of radius ‘r_{0}’ is
The axial ratio (c/a) of an ideal hexagonal closed packing is
The potential energy of a diatomic molecule in terms of interatomic separation R is given by die equilibrium separation is obtained as
1 docs34 tests

1 docs34 tests
