Aligarh Muslim University (AMU) 2011 Entrance Exams Gate Entrance Exam admission test dfet -2012 - Question Paper
Tuesday, 15 January 2013 01:20Web
1.A beam of 450 nm light is incident on a metal having work function two eV and placed in a magnetic field B.If the most energetic electrons emitted are bent into circular arc of radius 0.2 m,find B ?
a)2.36*10^-4 T. b)1.46*10^-5 T.c)6.9*10^-5 T.d)9.2*10^-6 T
2.The de Broglie wave length is provided by.........?
3.Which of the truth table corresponds to NAND gate?
4.The range of nuclear force is of the order of..?
a)2*10^-10 m.b)1.5*10^-20 m.c)1.2*10^-4 m.d)1.4*10^-15 m
5.What is the momentum of photon having frequency 1.5*10^13
6.The 2 headlights of an approaching cars are 1.4 m apart.At what maximum distance will the eye resolve them.Assume that the pupil diameter is 5.00 mm and the wavelength of light is 550 nm.
a)5 km. b)10 km. c)8 km. d)5.3 km
7.Find the wavelength of the light that may excite an electron in the valance band of diamond to the conduction band.The energy gap is 5.50 eV.
a)226nm. b)312nm. c)432nm. d)550nm.
8.A copper wire of length 50.0 cm and total resistance of 1.1*10^-2 ohm is formed into a circular loop and placed perpendicular to a uniform magnetic field that is increasing at the constant rate of 10.0 mT/s.At what rate is thermal energy generated in the loop ?
9.An electron is moving at a speed of 100 m/s along the X-axis through uniform electric and magnetic fields.The magnetic field is directed along the Z-axis and has magnitude 5.0 T.In unit-vector notation,what is the electric field?
10.The half life of 92U 238 undergoing alpha decay is 1.5*10^17 sec. What is the activity of 238 gm sample of 92U238.
11.An intrinsic semiconductor has a resistivity of 0.5 ohm m at room temperature .Find the intrinsic carrier concentration if the mobilities of the electrons and the holes are 0.39 m^2/volt-sec.and 0.11 m^2/volt-sec respectively.
12.The wavelength of spectral line coming from a distant star shifts from 600nm to 600.1nm.The velocity of the star relative to earth is..?
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