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The photoelectric threshold wavelength of a metal is 230 nm. Determine the maximum kinetic energy in joule and in eV of the ejects electron for the metal surface when it is exposed to a radiation of wavelength 180 nm.
[Planck’s constant : h = 6.63 * 10-34 Js, Velocity of light : C = 3 * 108 m/s.]
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A horizontal disc is freely rotating about a transverse axis passing through its centre at the rate of 100 revolutions per minute. A 20 gram blob of wax falls on the disc and sticks to the disc at a distance of 5 cm from its axis. Moment of intertia of the disc about its axis passing through its centre of mass is 2 x 10-4 kg m2. Calculate the new frequency of rotation of the disc.
Concept: undefined >> undefined
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The moment of inertia of a thin uniform rod of mass M and length L, about an axis passing through a point, midway between the centre and one end, perpendicular to its length is .....
(a)`48/7ML^2`
(b)`7/48ML^2`
(c)`1/48ML^2`
(d)`1/16ML^2`
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When a transverse wave on a string is reflected from the free end, the phase change produced is ..............
(a) zero rad
(b) ` pi/2 ` rad
(c) `(3pi)/4` rad
(d) `pi` rad
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Two particles perform linear simple harmonic motion along the same path of length 2A and period T as shown in the graph below. The phase difference between them is ___________.
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A wheel of moment of inertia 1 Kgm2 is rotating at a speed of 40 rad/s. Due to friction on the axis, the wheel comes to rest in 10 minutes. Calculate the angular momentum of the wheel, two minutes before it comes to rest.
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With a neat labelled diagram, show that all harmonics are present in an air column contained in a pipe open at both the ends. Define end correction.
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Explain the rise of liquid in the capillary on the basis of pressure difference.
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In a cyclotron, magnetic field of 3·5Wb/m2 is used to accelerate protons. What should be the time interval in which the electric field between the Dees be reversed?
(Mass of proton = 1· 67 x 10-27Kg, Charge on proton =1·6x10-19c).
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In a cyclotron, magnetic field of 3·5Wb/m2 is used to accelerate protons. What should be the time interval in which the electric field between the Dees be reversed?
(Mass of proton = 1· 67 x 10-27Kg, Charge on proton =1·6x10-19c).
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State formula and S.I. unit of Magnetization.
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State formula and S.I. unit of Magnetization.
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Find the value of energy of electron in eV in the third Bohr orbit of hydrogen atom.
(Rydberg's constant (R) = 1· 097 x 107m - 1,Planck's constant (h) =6·63x10-34 J-s,Velocity of light in air (c) = 3 x 108m/ s.)
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A pipe which is open at both ends is 47 cm long and has an inner diameter 5 cm. If the speed of sound in air is 348 m/s, calculate the fundamental frequency of air column in that pipe.
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A solid cylinder of uniform density of radius 2 cm has mass of 50 g. If its length is 12 cm, calculate its moment of inertia about an axis passing through its centre and perpendicular to its length.
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In Young' s experiment the ratio of intensity at the maxima and minima . in the interference pattern is 36 : 16. What is the ratio of the widths of the two slits?
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Calculate the density of paraffin oil, if glass capillary of diameter 0.25 mm dipped in paraffin oil of surface tension 0.0245 N/m rises to a height of 4 cm. (Angle of contact of paraffin with glass = 28° and acceleration due to gravity = 9.8 m/s2.)
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A wire of density ‘ρ’ and Young’s modulus ‘Y’ is stretched between two rigid supports separated by a distance ‘L’ under tension ‘T’. Derive an expression for its frequency in fundamental mode. Hence show that `n=1/(2L)sqrt((Yl)/(rhoL))` where symbols have their usual meanings
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A pipe open at both ends resonates to a frequency ‘n1’ and a pipe closed at one end resonates to a frequency ‘n2’. If they are joined to form a pipe closed at one end, then the fundamental frequency will be ______.
(A) `(n_1n_2)/(2n_2+n_1)`
(B) `(2n_2n_1)/(2n_2+n_1)`
(C) `(2n_2n_1)/(n_1+n_2)`
(D) `(n_2+2n_1)/(n_1n_2)`
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Find the wave number of a photon having energy of 2.072 eV
Given : Charge on electron = 1.6 x 10-19 C,
Velocity of light in air = 3 x 108 m/s,
Planck’s constant = 6.63 x 10-34 J-s.
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