Light of wavelength 4000 A0 is incident on a metal plate whose work function is 2 eV. The maximum kinetic energy of the emitted photoelectrons would be
Q4.In a Milikan’s oil drop apparatus an oil drop of radius 6 ×10−5m and of density 0.85 ×10−5 kg/m3 is seen to fall freely (without any field). The velocity of drop, given viscosity of air to be 1.83×10−5N−s/m2 and neglecting the effect of up thrust force due to air, is
Answer : Option AExplaination / Solution: No Explaination.
Q5.If the wavelength of light incident on photo-electric cell be reduced from 4000A0 to3600A0,then what will be the change in the cut off potential. (h=6.6×10−34J−s,c=3.0×108m/s,e=1.6×10−19C)
Answer : Option BExplaination / Solution: No Explaination.
When an electron enters a magnetic field of 0.01 T with a speed of 107ms−1 it describes a circle of radius 6 mm there. Then specific charge of the electron is given by
1.If an electron moving with a speed of 2.5×107ms−1 is deflected by an electric field of 1.6 k V m−1perpendicular to its circular path, then e/m for the electron will be (given radius of circlar path = 2.3 m)
Answer : Option CExplaination / Solution:
Electric field provide required centripetal force for circular motion