List of top Questions asked in JEE Main

The negation of the Boolean expression ((~ q) ∧ p) ⇒ ((~ p) ∨ q) is logically equivalent to:

If the line y = 4 + kx, k > 0, is the tangent to the parabola y = x – x² at the point P and V is the vertex of the parabola, then the slope of the line through P and V is:

The value of \( tan^{-1}(\frac{cos\frac{15}{4}-1}{sin(\frac{π}{4})} )\) is equal to:

The line y = x + 1 meets the ellipse \(\frac{x^2}{4}+\frac{y^2}{2}=1\) at two points P and Q. If r is the radius of the circle with PQ as diameter then (3r)² is equal to

In a potentiometer arrangement, a cell gives a balancing point at 75 cm length of wire. This cell is now replaced by another cell of unknown emf. If the ratio of the emf’s of two cells respectively is 3 : 2, the difference in the balancing length of the potentiometer wire in above two cases will be _____ cm.

A metre scale is balanced on a knife edge at its centre. When two coins, each of mass 10 g are put one on the top of the other at the 10.0 cm mark the scale is found to be balanced at the 40.0 cm mark. The mass of the metre scale is found to be \(x\times 10^{-2}\) kg. The value of x is _________.

SO₂Cl₂ in reaction with an excess water results in the acidic mixture
SO₂CL₂+2H₂O\(\rightarrow\)H₂SO₄+2HCL
16 moles of NaOH is required for the complete neutralization of the resultant acidic mixture. The number of moles of SO₂Cl₂ used is

Which of the following sets of quantum numbers is not allowed?

The depression in the freezing point observed for a formic acid solution of concentration 0.5 mL L^–1 is 0.0405°C. Density of formic acid is 1.05 g mL^–1. The Van’t Hoff factor of the formic acid solution is nearly (Given for water k_f = 1.86 k kg mol^–1)

20 mL of 0.1 M NH₄OH is mixed with 40 mL of 0.05 M HCl.The pH of the mixture is nearest to(Given :K_b(NH₄OH) = 1×10^–5,log2 = 0.30,log3 = 0.48, log5 = 0.69,log7 = 0.84,log11 = 1.04)

Match List-I with List-II.

List-I	List-II
(A) N₂(g) + 3H₂(g) → 2NH₃(g)	(I) Cu
(B) CO(g) + 3H₂(g) → CH₄(g) + H₂O(g)	(II) Cu/ZnO – Cr₂O₃
(C) CO(g) + H₂(g) → HCHO(g)	(III) Fe_xO_y + K₂O + Al₂O₃
(D) CO(g) + 2H₂(g) → CH₃OH(g)	(IV) Ni

Choose the correct answer from the options given below :

The IUPAC nomenclature of an element with electronic configuration [Rn] 5f¹⁴6d¹7s² is

The compound(s) that is(are) removed as slag during the extraction of copper is
(A)CaO,(B)FeO,(C)Al₂O₃,(D)ZnO,(E)NiO
Choose the correct answer from the options given below :

The reaction of H₂O₂ with potassium permanganate in acidic medium leads to the formation of mainly

Choose the correct order of density of the alkali metals.

The geometry around boron in the product ‘B’ formed from the following reaction is

The interhalogen compound formed from the reaction of bromine with excess of fluorine is a :

The photochemical smog does not generally contain :

A compound’A’ on reaction with ‘X’ and ‘Y’ produces the same major product but differentby product’a’ and ‘b’. Oxidation of’a’ gives a substance produced by ants.

Most stable product of the following reaction is :

Which one of the following reactions does not represent correct combination of substrateand product under the given conditions?

An organic compound ‘A’ on reaction with NH₃ followed by heating gives compound B. Which on further strong heating gives compound C(C₈H₅NO₂). Compound C on sequential reaction with ethanolic KOH, alkyl chloride and hydrolysis with alkali gives a primary amine. The compound A is :

Melamine polymer is formed by the condensation of :

During the denaturation of proteins, which of these structures will remain intact?