Which of the following is correct for light diverging from a point source?
(a) The intensity decreases in proportion with the distance squared.
(b) The wave front is parabolic.
(c) The intensity at the wavelength does not depend on the distance.
(d) None of these.
(a) The intensity decreases in proportion with the distance squared.
(b) The wave front is parabolic.
(c) The intensity at the wavelength does not depend on the distance.
(d) None of these.
(a) The intensity decreases in proportion with the distance squared.
Which of the following is conserved when light waves interference?
(a) phase.
(b) intensity.
(c) amplitude.
(d) none of these.
Which of the following is conserved when light waves interfere?
(a) phase
(b) intensity
(c) amplitude
(d) none of these
For sustained interference, we need two sources which emit radiations:
(a) of the same intensity
(b) of the same amplitude
(c) having a constant phase difference
(d) None of these
An optically active compound
(a) rotates the plane of polarised light.
(b) changes the direction of polarised light.
(c) does not allow plane polarised light to pass through.
(d) none of these.
Which of the following statements indicates that light waves are transverse?
(a) Light waves can be polarised
(b) Light waves can show interference
(c) Light waves undergo diffraction
(d) They travel in the vacuum
An optically active compound
(a) rotates the plane of polarised light
(b) changes the direction of polarised light
(c) does not allow plane polarised light to pass through
(d) none of these
What type of wave front will emerge from any distant source of light?
i. Spherical wave front
ii. Cylindrical wave front
iii. Plane wave front
iv. None of these
In the diffraction pattern due to single slit, at the position of 2nd maximum the path difference between the wavelets from the opposite edges of the slit is
I. 5λ/2
II. 3λ/2
III. 2λ
IV. λ
If the width of the slit in single slit diffraction experiment is doubled, then the central maximum of diffraction pattern becomes:
(A) broader and brighter
(B) broader and fainter
(C) sharper and fainter
(D) sharper and brighter
Two wires of same length are shaped into a square and a circle. If they carry same current, the ratio of their magnetic moment-
a) 2:π
b)π:2
c) 4:π
d) π:4.
Two currents loops are concentric and lie in the same plane. The current in the outer loop is anti clockwise and increasing with time. The induced current in the inner loop ,is
(a) Clockwise
(b) Zero
(c) Counter-clockwise
(d) None of these
In the figure the net electric flux through the area... when the system is in air. On immersing the system in water,the net electric flux through the area
Magnetic field lines form continuous closed loops
a) magnet is always a dipole
b) magnet is always a monopole
c) magnetic material is permeable
d) none of the above
The capacitance of earth, viewed as a spherical conductor of radius 6408 km is:
(a) 1420 μF
(b) 712 μF
(c) 680 μF
(d) 540 μF