Two protons A and B are placed in space between plates of a parallel plate capacitor charged upto V volts (See fig.) Forces on protons are 
and 
, then
|
(a) |
(b) |
(c) |
(d) Nothing can be said |
(c) 
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Curie temperature is the temperature above which
|
(a) A paramagnetic material becomes ferromagnetic |
|
(b) A ferromagnetic material becomes paramagnetic |
| (c) A paramagnetic material becomes diamagnetic |
|
(d) A ferromagnetic material becomes diamagnetic |
Nuclear forces are
|
(a) Short ranged attractive and charge independent |
|
(b) Short ranged attractive and charge dependent |
|
(c) Long ranged repulsive and charge independent |
|
(d) Long ranged repulsive and charge dependent |
A beam of light of wavelength 600 nm from a distant source falls on a single slit 1 mm wide and the resulting diffraction pattern is observed on a screen 2 m away. The distance between the first dark fringes on either side of the central bright fringe is
|
(a) 1.2 mm |
(b) 1.2 cm |
(c) 2.4 cm | (d) 2.4 mm |
The average kinetic energy of the thermal neutrons is of the order of (Boltzmann's constant 
|
(a) 0.03 eV |
(b) 3 eV |
(c) 3 KeV |
(d) 3 MeV |
A cylindrical bar magnet is kept along the axis of a circular coil. If the magnet is rotated about its axis, then
|
(a) A current will be induced in a coil |
|
(b) No current will be induced in a coil |
|
(c) Only an e.m.f. will be induced in the coil |
|
(d) An e.m.f. and a current both will be induced in the coil |
The magnetic field at the centre of a circular coil of radius r is π times that due to a long straight wire at a distance r from it, for equal currents. Figure here shows three cases : in all cases the circular part has radius r and straight ones are infinitely long. For same current the B field at the centre P in cases 1, 2, 3 have the ratio
|
(a) |
(b) |
|
(c) - |
(d) |
