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
(a) 0.4 mm
(b) 0.5 mm
(c) 0.6 mm
(d) 0.8 mm
(c) 0.6 mm
In Young’s double slit experiment the distance between the slit and the screen is doubled and the separation between the slit is reduced to half. The fringe width:
(a) is doubled
(b) become four time
(c) is halved
(d) remain unchanged
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
In Young’s double slit experiment, the fringe width is β . If the entire arrangement is now placed inside a liquid of refractive index μ , the fringe width will become
(a) μ β
(b) β/μ
(c) β/μ+1
(d) β/μ−1
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
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 separation between the slits is 0.1 mm, the wavelength of light used is 600 nm and the interference pattern is observed on a screen 1 m away. Find the separation between bright fringes.
(A) 6.0 mm
(B) 6.6 mm
(C) 6 m
(D) 60 cm
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
A parallel plate air capacitor has a capacitance 18μF. If the distance between the plates is tripled and a dielectric medium is introduced, the capacitance becomes 72μF. The dielectric constant of the medium is
(a) 4
(b) 9
(c) 12
(d) 2
The electric potential of earth is taken to be zero, because earth is a good
(a) insulator
(b) conductor
(c) semiconductor
(d) dielectric
The charges on two spheres are +7mC and –5mC respectively. They experience a force F. If each of them is given an additional charge of –2mC, the new force of attraction will be
What is the angle between the electric dipole moment and electric field strength due to it on the axial line?
(A) \(0^\circ\)
(B) \(90^\circ\)
(C) \(180^\circ\)
(D) None of these
Wavefront is the locus of all points, where the particles of the medium vibrate with the same
(a) phase.
(b) amplitude.
(c) frequency.
(d) period.
To observe diffraction, the size of the obstacle
(a) should beX/2, where X is the wavelength.
(b) should be of the order of wavelength.
(c) has no relation to wavelength.
(d) should be much larger than the wavelength.
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