In double –slit experiment the distance of the second dark fringe from the central line is 3 mm. The distance of the fourth bright fringe from the central line is
(A) 6 mm
(B) 8mm
(C) 12 mm
(D) 16 mm
(A) 6 mm
(B) 8mm
(C) 12 mm
(D) 16 mm
(B) 8mm
In Young’s double-slit experiment, the phase difference between the light waves reaching the third bright fringe from the central fringe will be (λ=6000 Å)
(a) zero
(b)2
(c) 4
(d) 6
In a Young’s double slit experiment the distance between the slit is 1 mm and the distance of screen from the slit is 1 m. If light of wavelength 6000 A is used then the fringe width is:
(a) 0.4 mm
(b) 0.5 mm
(c) 0.6 mm
(d) 0.8 mm
In Young’s double slit experiment, the fringe width is β. if the entire arrangement is placed in a liquid of refractive index n, then the fringe width becomes
(A) n β
(B) β /(n+1)
(C) β /(n-1)
(D) β /n
Two slits in Young’s double slit experiment have widths in the ratio 81:1. The ratio of the amplitudes of light waves is
(a) 3 :1
(b) 3 : 2
(c) 9 :1
(d) 6:1
When light suffers reflection at the interface between water and glass, the change of phase in the reflected wave is
(a) zero..
(b) π.
(c) π/2.
(d) 2π.
Ratio of intensities of two waves are given by 4 :1. Then the ratio of the amplitudes of the two waves.
(a) 2 : 1
(b) 1 : 2
(c) 4 : 1
(d) 1 : 4
Two interfering beams have intensities in the ratio of 9:4. Then the ratio of maximum to minimum intensity in the interference pattern is
(A) 25:1
(B) 13:5
(C) 5:1
(D) 3:2
The electric potential of earth is taken as:
(a) zero
(b) infinity
(c) unity
(d) None of these
A compass needle whose magnetic moment is 60 A m² pointing geographical north at a certain place, where the horizontal component of the earth’s magnetic field is 40 μWb m², experiences a torque
0.2 × 10⁻³ Nm. The declination at this place is
A single slit diffraction pattern is obtained using a beam of red light What happened if the red light is replaced by the blue light?
(a) There is no change in diffraction pattern
(b) Diffraction fringes become narrower and crowded
(c) Diffraction fringes become broader and farther apart
(d) The diffraction pattern disappear
How does the fringe width alter, if the entire Young’s double slit experimental set up is completely immersed into water ?
I. Increases
II. Decreases
III. Remains same
IV. None of these
A glass rod acquires charge by rubbing it with silk cloth. The charge on glass rod is due to :
(A) Friction
(B) Conduction
(C) Induction
(D) Radiation
The penetration of light into the region of geometrical shadow is known as
a. Interference of light
b. Diffraction of light
c. Refraction of light
d. Polarization of light
A charge Q is enclosed by a Gaussian spherical surface of radius R. If the radius is doubled, then the outward electric flux will
(A) Increase four times
(B) be reduced to half
(C) remain the same
(D) Be doubled