In a double slit interference pattern, the first maxima for infrared light would be
a. at the same place as the first maxima for green light
b. closer to the centre than the first maxima for green light
c. farther from the centre than the first maxima for green light
d. infrared light does not produce an interference pattern
a. at the same place as the first maxima for green light
b. closer to the centre than the first maxima for green light
c. farther from the centre than the first maxima for green light
d. infrared light does not produce an interference pattern
c. farther from the centre than the first maxima for green light
In a double slit interference pattern, the first maxima for infrared light would be
(a) at the same place as the first maxima for green light
(b) closer to the centre than the first maxima for green light
(c) farther from the centre than the first maxima for green light
(d) infrared light does not produce an interference pattern
A double slit interference experiment is carried out in air and the entire arrangement is dipped in water. The fringe width
(a) increases
(b) decreases
(c) remains unchanged.
(d) fringe pattern disappears
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 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
To obtain a sustained interference pattern we require two sources which emit radiation of
(A) the same frequency
(B) nearly same frequency
(C) the same frequency having a definite phase relationship
(D) different wavelengths
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
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
When a compact disc is illuminated by a source of white light , colored lines are observed. This is due to
I. Interference
II. Diffraction
III. Dispersion
IV. Refraction
If a magnet is cut perpendicular its length into equal parts ,then the pole strength of each pole of the magnet
a) becomes double
b) remains same
c) becomes half
d) None of the above
Electric potential at a distance r from the point charge is proportional to
1. \(r^2\)
2. r-1
3. r0
4. r+1
An alternating e.m.f. of angular frequency ω is applied across an inductance. The instantaneous power developed across it has an angular frequency
(a) ω/4
(b) ω/2
(c) ω
(d) 2 ω
The insulation property of air, breaks down at E=3x \(10^6\)V/m. The maximum charge that can be given to a sphere of radius 2.5 m is approximately
(A) 2x \(10^{-2}\)C
(B) 2x \(10^{-3}\)C
(C) 3x \(10^{-6}\)C
(D) 3x \(10^{-5}\)C
\(10^6\) electrons are taken out of a pith ball. The positive charges on the pith ball is
A. 1.6x \(10^{-13}\) C
B. 1.6x \(10^{-19}\) C
C. 1.6x \(10^{-25}\) C
D. none of these
A cylindrical bar magnet is rotated about its axis in the figure. A wire is connected from the axis and is made to touch the cylindrical surface through a contact. Then