The potential energy of an electron in the first excited state of hydrogen atom is -6.8 eV. The kinetic energy of the electron in its ground state will be :

The power of the composite lens made of two thin lenses of focal lengths \(f_1\) and \(f_2\) placed in contact will be:

Select scalar quantities from the following:
A. electric flux
B. Electric current
C. Current density
D. Electromagnetic force
Choose the correct answefrom the options given below:

The statement that is NOT true about induced emf is :

If a p-n junction is forward biased, then what is the direction of diffusion and drift current across the junction?

Choose the correct relation between drift velocity (\( v_d \)) and current density (\( J \)) from the following:

A strong magnetic field is applied on a stationary electron :

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The transition metals and their compounds are known for their catalytic activity. This activity is ascribed to their ability to adopt multiple oxidation states and to form complexes. Vanadium(V) oxide (in Contact Process), finely divided iron, and nickel (in Catalytic Hydrogenation) are some of the examples. Catalysts at a solid surface involve the formation of bonds between reactant molecules and atoms of the surface of the catalyst (first row transition metals utilise 3d and 4s electrons for bonding). This has the effect of increasing the concentration of the reactants at the catalyst surface and also weakening of the bonds in the reacting molecules (the activation energy is lowering). Also because the transition metal ions can change their oxidation states, they become more effective as catalysts.
Which of the following catalyses the oxidation of SO2 in the manufacture of sulphuric acid?

In a LPP , if the objective function \(Z=a x+b y\) has the same maximum value at two corner points of the feasible region, then the number of points at which \(Z_{\max }\) occurs is:

For \(x>y>0\), if \(x^5 y^6=(x+y)^{11}\), then \(\frac{d^{2} y}{d x^2}\) is

Match List I with List II

\multicolumn1|c|\(LIST\)\(I\)	\multicolumn1|c|\( LIST\)\(II\)
A. \(Cu\)	I. \(+ 3\)
B. \(Sc\)	II. \(+ 7\)
C. \(Mn\)	III. \(+ 2\)
D.\(Fe\)	IV. \(+ 1\)

Choose the correct answer from the options given below:

Answer the question on basis of passage given below :
Molecular nitrogen is very little reactive chemically. During lightning discharge, atmospheric nitrogen and oxygen combines to form nitric oxide which also combines with oxygen to form nitrogen dioxide. Both NO and \(NO _2\) constitute smog which is very poisonous. It can cause burning sensation in the eyes and adversely affect respiratory system.
Oxidation state of nitrogen in nitric oxide and nitrogen dioxide respectively is :

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Carbonyl compounds such as aldehydes, ketones, and carboxylic acids play an important role in the biochemical process of plants and animal kingdom.
Many aldehydes and ketones find applications in dye, perfumery and other industries.
The carbonyl carbon atom is \(s p^2\)-hybridized forming three sigma and one pi-bond with oxygen.
C-O bonds are polar bond due to high electronegativity of oxygen than carbon.
Hence the carbonyl carbon behaves as an electrophilic center and oxygen as a nucleophilic centre.
Primary and secondary alcohols yield aldehydes and ketones respectively upon oxidation with variety of oxidizing agents.
The boiling points of aldehydes and ketones differ from hydrocarbons and ethers.
Aldehydes and ketones undergo nucleophilic addition reaction due to presence of electrophilic carbonyl carbon.
Nucleophile and a proton add across the carbon oxygen double bond.
In polar C-O bond in carbonyl compounds, the nature of carbon and oxygen atom is