The condition for Fraunhoffer diffraction from a single slit is that the light wave-front incident on a slit should be
(A) Spherical
(B) Cylindrical
(C) Plane
(D) Rectangular
(A) Spherical
(B) Cylindrical
(C) Plane
(D) Rectangular
(C) Plane
The wave-front due to source situated at the infinity is
(A) Spherical
(B) Cylindrical
(C) Plane
(D) Rectangular
The wavefront due to a source situated at infinity is
(a) spherical
(b) cylindrical
(c) planar
(d) circular
The locus of all the points vibrating in same phase of oscillation is called
(A) Wavelet
(B) Wavefront
(C) Wavetrain
(D) Rays
In the Young double slit experiment, the fringe pattern as seen on the screen is:
(A) Parabola
(B) Hyperbola
(C) Ellipse
(D) Spiral
The phenomenon of diffraction can be treated as interference phenomenon if the number of coherent sources is:
(A) one
(B) two
(C) zero
(D) infinity
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
If the 8th bright fringe of light of wavelength \(λ_1\) coincides with the 9th bright fringe of light of the wavelength \(λ_2\) in young’s double experiment, then the possible wavelengths of visible light are
(A) 400nm and 450nm
(B) 425nm and 400nm
(C) 400nm and 425 nm
(D) 450nm and 400nm
the magnitude of a charge q at the center of two equal and like charges Q so that the three charges are in equilibrium
A. Q
B. Q/2
C. Q/4
D. –Q/4
The electric potential of earth is taken as:
(a) zero
(b) infinity
(c) unity
(d) None of these
\(10^6\) 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 current carrying small loop behaves like a small magnet. If A be its area and M its magnetic moment, the current in the loop will be
a) M/A
b) A/M
c) MA
d) A²M
The ratio of intensities at minima to the maxima in young’s double slit experiment is 9 : 25. Find the ratio of the widths of two slits.
(A) 16: 1
(B) 1: 16
(C) 4 : 1
(D) 1 : 4
Two copper spheres of the same radius, one solid and the other hollow, are charged to the same potential. Which will have more charge?
(a) Solid sphere
(b) Hollow sphere
(c) Both will have an equal charge
(d) None of these