How can fringe width increase in Young's double slit experiment?

Two light beams of intensities in the ratio 25:9 are allowed to interfere. The ratio of the intensities of maxima and minima will be

A solenoid has a core of a material with a relative permeability of 500 . The windings of the solenoid are insulated from the core and carry a current of 0.5 A . If the number of turns is 2000 per metre, the magnetic intensity is

If an electron and a photon have energy, then,
(A) Electrons and photons both have wavelengths
(B) Electron and photon both have momentum
(C) Both electron and photon do not have momenta
(D) The electron has energy and momentum and the photon has energy only
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An equiconvex lens has a focal length of 20 cm and its radius of curvature is 30 cm. Its refractive index is

Match List-I with List-II

List-I (Uses of electromagnetic waves)	List-II (Type of electromagnetic waves)
(A) Aircraft navigation	(I) Infrared waves
(B) Cellular phones	(II) Microwaves
(C) Remote switches for TV sets	(III) Ultraviolet rays
(D) LASIK eye surgery	(IV)  Radio waves

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Which phenomena proves the particle nature of photon?

The force between two small charged spheres having charges of \( 2 \times 10^{-7} \, \text{C} \) and \( 3 \times 10^{-7} \, \text{C} \), respectively, placed 30 cm apart in air would be.

If \(\left|\begin{array}{ccc}-a^2 & a b & a c \\ b a & -b^2 & b c \\ a c & b c & -c^2\end{array}\right|=k \cdot a^l b^m c^n\), then
Match List-I with List-II

List-I	List-II
(A) \(l=m=n=\)	(I) 10
(B) \(k+l+m+n=\)	(II) 6
(C) \(k^2+l^2+(m-n)^2\)	(III) 2
(D) \(l^2+m^2+(n-k)=\)	(IV) 20

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Match List I with List II

LIST I (Name of interaction)	LIST II ('o' represents neutral, '+'represents benificial, '-'represents detrimental)
A. Commensalism	I. -,-
B. Competition	II. +,+
C. Mutualism	III. -,0
D. Amensalism	IV. +,0

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Select the correct statement/s about sporopollenin found in pollen grain.
(A) The hard outer layer of pollen grains is made up of sporopollenin.
(B) It is one of the most resistant organic material known.
(C) It does not withstand high temperature and strong acids.
(D) No enzyme can degrades it.
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The oxidation number of Co in the complex \(\left[ Co \left( H _2 NCH _2 CH _2 NH _2\right)_3\right]_2\left( SO _4\right)_3\) is:

Read the passage carefully and answer the given questions.
DNA Fingerprinting
Polymorphism in DNA sequence is the basis of genetic mapping of the human genome as well as of DNA fingerprinting. DNA fingerprinting involves identification of differences in some specific regions in the DNA sequence called repetitive DNA. It works on the principle of polymorphisms in DNA sequences. The repetitive DNA are separated from bulk genomic DNA. The bulk DNA forms a major peak and the other small peaks are referred to as satellite DNA. These repetitive/satellite DNA sequences show a high degree of polymorphisms and form the basis of DNA fingerprinting.
DNA fingerprinting is meant for: