JEE Main entrance exam Question Bank Solutions

Out of the following, which type of interaction is responsible for the stabilisation of the α-helix structure of proteins?

A proton and a Li³⁺ nucleus are accelerated by the same potential. If λ_Li and λ_P denote the de Broglie wavelengths of Li³⁺ and proton respectively, then the value of `λ_("Li")/(λ_"P")` is x × 10⁻¹. The value of x is ______. [Rounded-off to the nearest integer]

[Mass of Li³⁺ = 8.3 mass of proton]

The correct structure of Ruhemann's Purple, the compound formed in the reaction of ninhydrin with proteins is:

The number of lone pairs of electrons on the central I atom in `"I"_3^-` is ______.

Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R:

Assertion A: The H-O-H bond angle in water molecule is 104.5°.

Reason R: The lone pair-lone pair repulsion of electrons is higher than the bond pair-bond pair repulsion.

In the light of the above statements, choose the correct answer from the options given below:

When light of wavelength 248 nm falls on a metal of threshold energy 3.0 eV, the de-Broglie wavelength of emitted electrons is ______ A°. (Round off to the Nearest Integer)

[Use: `sqrt3` = 1.73, h = 6.63 × 10⁻³⁴ Js, m_e = 9.1 × 10⁻³¹ kg, c = 3.0 × 10⁸ ms⁻¹, 1eV = 1.6 × 10⁻¹⁹ J]

The total number of negative charge in the tetrapeptide, Gly-Glu-Asp-Tyr at pH 12.5 will be ______. (Integer answers)

Coupling of benzene diazonium chloride with 1-naphthol in alkaline medium will give:

Identify X and Y in the following reaction:

The de Broglie's wavelength of electron emitted by metal will be ______ Å whose threshold frequency is 2.25 × 10¹⁴ Hz when exposed to visible radiation of wavelength 500 nm.

The size of a raw mango shrinks to a much smaller size when kept in a concentrated salt solution. Which one of the following processes can explain this?

The migration of dispersion medium under the influence of an electric potential is called ______.

Kjeldahl's method is used in the estimation of ______.

In the following structure, the percentage of the 's' character in the lone pair occupy by the oxygen atom is ______.

Given: Cos θ = −0.99

The major product of the following reaction is:

The energy released in joule and MeV in the following nuclear reaction,

\[\ce{^2_1{H} + ^2_1{H} -> ^3_2{He} + ^1_0{n}}\]

(Assume that the masses of \[\ce{^2_1{H}}\], \[\ce{^3_2{He}}\] and neutron (n) respectively are 2.0141, 3.0160 and 1.0087 in amu) is ______ × 10⁻¹³ J.

The effective atomic number (EAN) of a metal carbonyl, m(CO)_x is 36. The atomic number of the metal is 26. The value of 'x' is ______.

The de Broglie wavelength of an electron in the 4^th Bohr orbit is ______.

Among the following substituted silanes, which one will give rise to cross linked silicone polymer on hydrolysis?

The metal salts formed during softening of hard water using Clark's method are ______.