Identify the correct statements.
(A) A concave mirror is preferred over a plane mirror for the purpose of shaving.
(B) The absolute refractive index of a medium can be less than unity.
(C) Snell's law gives the relative refractive index of a medium.
(D) When a convex lens is placed inside a transparent medium of refractive index greater than that of its own material, it behaves as a diverging lens.
Choose the correct answer from the options given below:

In a hydrogen atom, an electron moves in an orbit of radius \( 5 \times 10^{-11} \text{ m} \) with a speed of \( 2.2 \times 10^6 \text{ m/s} \). The equivalent current is

If the A.C. main supply is given to be 220 V in a circuit. The average emf during a positive half cycle is

Which of the following pair of nuclides are Isobars?

An electric dipole of length 2 cm is placed at an angle of \(30^\circ\) with an electric field \(3 \times 10^5 \text{ N C}^{-1}\). If the dipole experiences a torque of \(9 \times 10^{-3} \text{ N m}\), the magnitude of either charge of the dipole is

Which of the following is not an EM wave ?

Which are the correct statements from given below:
A. Kirchhoff's junction rule is based on conservation of charge
B. Current is a vector quantity.
C. Current density is a vector quantity.
D. Resistance doesn't depend on dimension of conductor.
E. Resistivity depends on temperature.

If \(y^{\frac{1}{m}}+y^{-\frac{1}{m}}=2 x\), then the value of \(\left(x^2-1\right) \frac{d^2 y}{d x^2}+x \frac{d y}{d x}\) is :

Answer the question on basis of passage given below :
The noble gases have closed shell electronic configuration and are monatomic gases under normal conditions. The low boiling points of lighter noble gases are due to the weak dispersion forces between the atoms and the absence of other inter atomic interaction. The direct reaction of xenon with fluorine leads to a series of compounds with oxidation numbers \(+2, +4\) and \(+6\).
\(\text{XeF}_4\) reacts violently with water to give \(\text{XeO}_3\). The compound of Xenon exhibit stereoisomerism and their geometries can be deduced considering the total number of electrons in the valence shell.
\(X e F _4 \quad\) and \(X e F _6 \quad\) are expected to be :

The work function for a metal surface is 8.28 eV . The threshold wavelength for this metal surface is :

A convex lens \(\left(n_g=1.5\right)\) of focal length 10 cm in air when immersed in a liquid behaves as a diverging lens of focal length 45 cm . The refractive index of the liquid :

Arrange the following ligands in decreasing order of field strength in spectrochemical series.
(A) Br\(^-\)
(B) H\(_2\)\(\mathrm{O}\)
(C) OH\(^-\)
(D) CO
Choose the correct answer from the options given below:

Read the passage carefully and answer the questions based on the passage:
Alcohols are versatile compounds as they can act as both nucleophile and electrophile. They undergo reactions based on cleavage of \(\mathrm{O}-\mathrm{H}\) and \(\mathrm{C}-\mathrm{O}\) bonds. The cleavage of \(\mathrm{O}-\mathrm{H}\) bond reflects the acidic character of alcohols. However they are weaker acids than water, phenol and carboxylic acids. Alkoxide ion formed by loss of proton from the OH group of alcohols reacts with water to form the corresponding conjugate acid - base pair. They act as Bronsted base due to presence of unshared electron pairs on oxygen.Both alcohols and phenol react with carboxylic acids, acid chlorides and anhydrides to form esters. The introduction of acetyl group in alcohols or phenol is known as acetylation. Alcohols react with hydrogen halides to form alkyl halides which form the basis of Lucas test. They also undergo acid catalyzed dehydration to form alkenes. Alcohols can be easily oxidized with variety of oxidizing agents. The nature of the product depends on the type of oxidizing agent and the nature of alcohol.
Lucas reagent is