# +2 Physics - Random One Mark Collection - Set 7

Questions from 51 - 60 are provided in this set of Physics questions collection.

51) If the minimum wavelength of X-rays produced in a Coolidge tube is 0·62 A. the operating potential is

a) 0.2 kV
b) 2 kV
c) 10 kV
d) 20 kV

52) Resistance of a metal wire of length 10 cm is 2 ohm . If the wire is stretched uniformly to 50 cm, the resistance is

a) 10 ohm
b) 25 ohm
c) 50 ohm
d) 5 ohm

53) Which of the following particles is a lepton ?

a) Proton
b) Electron
c) pi-Meson
d) Neutron

54) The reactance offered by 300 mH inductor to an AC supply of frequency 50 Hz is

a) 94.2 ohm
b) 1046 ohm
c) 9420 ohm
d) 104.6ohm

55) A hollow metallic spherical shell carrying an electric charge produces no electric field at points

a) inside the sphere
b) on the surface of the sphere
c) at infinite distance from the centre of the sphere
d) outside the sphere

56) The binding energy of 25Fe56 nucleus is

a) 88 MeV
b) 493 MeV
c) 41.3 MeV
d) 8.8 MeV

57) The number of electric lines of force originating from a charge of 1 microcoulomb is

a) 1·129 x 1015
b) 6·25 x 1018
c) 1.6 x 10-19
d) 8·85 x 10-12

58) The forbidden energy gap for germanium is of the order of

a) 0·7 eV
b) 1·1 eV
c) 0·3 eV
d) 10 eV

59) Unpolarised light passes through a tourmaline crystal. The emergent light is analysed by an analyser. When the analyser is rotated through 90°, the Intensity oflight

a) remains uniformly dark
b) varies between maximum and minimum
c) varies between maximum and zero
d) remains uniformly bright

60) The law that governs the force between electric charges is