In an interference experiment, third bright fringe is obtained at a point on the screen with a light of 700 nm. What should be the wavelength of the light source in order to obtain 5th bright fringe at the same point
|
(a) 500 nm |
(b) 630 nm |
(c) 750 nm |
(d) 420 nm |
(d) 420 nm
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Rest mass energy of an electron is 0.54 MeV. If velocity of the electron is 0.8 c, then K.E. of the electron is
|
(a) 0.36 MeV |
(b) 0.41 MeV |
(c) 0.48 MeV |
(d) 1.32 MeV |
In an electroplating experiment, m gm of silver is deposited when 4 ampere of current flows for 2 minute. The amount (in gm) of silver deposited by 6 ampere of current for 40 second will be
|
(a) 4 m |
(b) m/2 |
(c) m/4 |
(d) 2 m |
Figures below show regular hexagons, with charges at the vertices. In which of the following cases the electric field at the centre is not zero
ABC is an equilateral triangle. Charges + q are placed at each corner. The electric intensity at O will be
|
(a) |
(b) |
(c) Zero |
(d) |
If two streams of protons move parallel to each other in the same direction, then they
|
(a) Do not exert any force on each other |
|
(b) Repel each other |
|
(c) Attract each other |
|
(d) Get rotated to be perpendicular to each other |
If 
and 
are the electric and magnetic field vectors of E.M. waves then the direction of propagation of E.M. wave is along the direction of
|
(a) |
(b) |
(c) |
(d) None of these |
