For a given surface the Gauss's law is stated as 
From this we can conclude that
|
(a) E is necessarily zero on the surface |
|
(b) E is perpendicular to the surface at every point |
|
(c) The total flux through the surface is zero |
|
(d) The flux is only going out of the surface |
(c) The total flux through the surface is zero
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A conductor ABOCD moves along its bisector with a velocity of 1 m/s through a perpendicular magnetic field of 1 wb/m2, as shown in fig. If all the four sides are of 1m length each, then the induced emf between points A and D is
|
(a) 0 |
(b) 1.41 volt |
(c) 0.71 volt |
(d) None of the above |
The work function of metal is 1 eV. Light of wavelength 3000 Å is incident on this metal surface. The velocity of emitted photo-electrons will be
|
(a) 10 m/sec |
(b) 1 |
(c) |
(d) |
The direction of current in an iron-copper thermocouple is
|
(a) From copper to iron at the hot junction |
(b) From iron to copper at the hot junction |
|
(c) From copper to iron at cold junction |
(d) No current will flow |
Compton effect shows that
|
(a) X-rays are waves |
(b) X-rays have high energy |
|
(c) X-rays can penetrate matter |
(d) Photons have momentum |
The north and south poles of two identical magnets approach a coil, containing a condenser, with equal speeds from opposite sides. Then
|
(a) Plate 1 will be negative and plate 2 positive |
|
(b) Plate 1 will be positive and plate 2 negative |
|
(c) Both the plates will be positive |
|
(d) Both the plates will be negative |
Astigmatism (for a human eye) can be removed by using
|
(a) Concave lens |
(b) Convex lens |
(c) Cylindrical lens |
(d) Prismatic lens |
