In a Young's double-slit experiment, the slits are separated by 0.56 mm and the screen is placed 2.8 m away from the slits. The distance between the central bright fringe and the fourth bright fringe is measured to be 1.2 cm. Determine the wavelength of light used in the experiment.

Velocity of light in diamond, glass and water decreases in the following order :

Which of the following frequency would be suitable for the beyond the horizon communication using sky waves?

What is the de-Broglie wavelength associated with an electron, accelerated through a potential difference of 10 kV

What is the radius of the path of an electron moving with velocity of \(3 \times 10^7\) m/s in a magnetic field of \(6 \times 10^{-4}\) T perpendicular to it?

The self inductance of a coil is 200 \( \mu \)H, current changes by 1 A in 0.05 sec. What is the emf produced?

A gaussian surface encloses three point charges \( q_1 = -14 \text{ nC}, q_2 = 78.85 \text{ nC} \) and \( q_3 = -56 \text{ nC} \). The electric flux for the gaussian surface due to these charges is

Which of the following genetic disorder is not a type of Mendelian disorder?

Let \(A=\left[a_{i j}\right]\) is given by \(A=\left[\begin{array}{ccc}1 & -1 & 2 \\ 3 & 4 & -5 \\ 2 & -1 & 3\end{array}\right]\). Then the matrix \(B=\left[b_{i j}\right]\), where \(b_{i j}\) = Minor of \(a_{i j}\) is:

Match List I with List II

List 1	List 2
A. Lanthanum	I. \(+3,+4\)
B. Praseodymium	I. +3
C. Neodymium	III. \(+2,+3,+4\)
D. Samarium	IV. \(+2,+3\)

Choose the correct answer from the options given below:

Arrange the given structures starting from chalazal end to micropylar end in a mature embryo sac?
(A) Central cell
(B) Antipodals
(C) Synergids
(D) Egg
Choose the correct answer from the options given below:

Read the passage given below and answer the question.
The transition elements which give the greatest number of oxidation states occur in or near the middle of the series. Manganese, for example, exhibits all the oxidation states from +2 to +7 . The lesser number of oxidation states at extreme ends stems from either too few electrons to lose or share (Sc, Ti) on too many d-electrons (hence fewer orbitals available in which to share electrons with others) for higher valence \(( Cu , Zn )\). Thus early in the series scandium (II) is virtually unknown and titanium (IV) is more stable than Ti (III) or Ti (II). At the other end, the only oxidation state of zinc is \(+ 2\) (no d electrons are involved). The maximum oxidation states of reasonable stability correspond in value to the sum of the s - and d-electrons upto manganese ( \(Ti ^{I V} O _2, V^V O _2^{+}, Cr ^{V I} O _4^{2-}\), \(Mn ^{\text {VII }} O _4\) ) followed by a rather abrupt decrease in stability of higher oxidation states, so that the typical species to follow are \(Fe ^{I I, I I I}, Co ^{I I, I I I}, Ni ^{I I}, Cu ^{I, I I}, Zn ^{I I}\).
The variability of oxidation states, a characteristic of transition elements, arises out of incomplete filling of d-orbitals in such a way that their oxidation states differ from each other by unity, e.g. \(V ^{I I}, V^{I I I}, V^{I V}, V^V\). This is in contrast with the variability of oxidation states of non transition elements where oxidation states normally differ by a unit of two.
An interesting feature in the variability of oxidation states of the d-block elements is noticed among the groups (groups 4 through 10). Although in the p-block, the lower oxidation states are favoured by the heavier members (due to inert pair effect), the opposite is true in the groups of dblock. For example, in group 6, \(Mo ( VI )\) and \(W ( VI )\) are found to be more stable than \(Cr ( VI )\). The \(Cr ( VI )\) in the form of dichromate in acidic medium is a strong oxidising agent, whereas \(MoO _3\) and \(WO _3\) are not.
Low oxidation states are found when a complex compound has ligands capable of \(\pi\)-acceptor character in addition to the \(\sigma\)-bonding. For example, in \(Ni ( CO )_4\) and \(Fe ( CO )_5\), the oxidation state of nickel and iron is zero.
Which amongst the following is a better oxidising agent than other ?

p-block elements are placed in groups 13 to 18 of the periodic table. Group 15 is nitrogen family.
Nitrogen makes various compounds like \(NH _3, HNO _3, N_2 O , NO _2\) etc. Phosphorus exists in the form of white and red phosphorus. White phosphorus glows in dark. \(PH _3\) gas is used as smoke screen. Group 16 is called oxygen family. Dry air contains \(21\% O_2\) gas by volume. Combined sulphur exists as sulphates such as gypsum, epsome salt, baryte etc. The allotropic forms of sulphur are Rhombic and monoclinic sulphur. \(S_2\) is paramagnetic like \(O_2\) and it stable at high temperature.
Group 17 is Halogen family. \(F_2\) is highly reactive, \(Cl _2\) is greenish yellow gas. Both \(SO _2\) and \(Cl _2\) are used for bleaching. Group 18 is Noble gas family but some noble gases also form compounds.
Complete hydrolysis of \(XeF _6\) gives HF and \(XeO _3\) as main products.
At elevated temperature \((\sim 1000 K)\) the dominant form of sulphur is :