The following experiment suggests that light propagates as waves

In a coil of self inductance 10 H, the rate of change of current is \( 4 \text{ A s}^{-1} \). The electromotive force (emf) induced in the coil will be

The angle of minimum deviation if the refracting angle of a prism is \(2θ\), and the refractive index of the material of the prism is \(\cot θ\) is:

An equiconvex lens has a focal length\(\frac{2}{3}\) times the radius of curvature of either surface. The refractive index of the material of the lens is :

In an AC generator, a 100 turns coil of area \( 0.10 \text{ m}^2 \) rotates at 50 Hz in a uniform magnetic field of 0.01 T. The maximum voltage generated in the coil is:

If the wavelength of light in an experiment on photoelectric effect is increased, then
(A) the photoelectric emissions will not take place
(B) the photoelectric emission may or may not take place
(C) the stopping potential will increase.
(D) the stopping potential will decrease
Choose the correct answer from the options given below:

A radioactive substance decays to \( \frac{1}{32} \text{th} \) of its initial activity in 30 days. Its half life period will be:

The calculated magnetic moment using the 'spin only' formula \(\mu=\sqrt{n(n+2)}\) for \(\mathrm{Cr}^{2+}\) and \(\mathrm{Fe}^{2+}\) respectively is

The value of \(\lambda\) so that the lines \(\frac{1-x}{3}=\frac{7 y-14}{2 \lambda}=\frac{z-3}{2}\) and \(\frac{7-7 x}{3 \lambda}=\frac{y-5}{1}=\frac{6-z}{5}\) are at right angle, is :

A 10 pF capacitor is connected to a 24 V battery. The electrostatic energy stored in the capacitor is:

Oral pills used by females for contraception consists of combination of:

Rusting occurs in the presence of water and air.

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 :