List of top Questions asked in JEE Main

Two transparent media having refractive indices 1.0 and 1.5 are separated by a spherical refracting surface of radius of curvature 30 cm. The centre of curvature of surface is towards denser medium and a point object is placed on the principle axis in rarer medium at a distance of 15 cm from the pole of the surface. The distance of image from the pole of the surface is _____ cm.

A series combination of resistor of resistance 100 Ω, inductor of inductance 1 H and capacitor of capacitance 6.25 µF is connected to an ac source. The quality factor of the circuit will be ______

The number density of free electrons in copper is nearly 8 × 10²⁸ m^-3. A copper wire has its area of cross section = 2 × 10^-6 m² and is carrying a current of 3.2 A. The drift speed of the electrons is _____ ×10^-6 ms^-1

Which of the following have same number of significant figures?
A. 0.00253
B. 1.0003
C. 15.0
D. 163
Choose the correct answer from the options given below

Arrange the following gases in increasing order of van der Waals constant 'a'
A. Ar
B. CH4
C. H₂O
D. C6H6
Choose the correct option from the following.

The correct reaction profile diagram for a positive catalyst reaction .

Henry Moseley studied characteristic X-ray spectra of elements. The graph which represents his observation correctly is
Given v = frequency of X-ray emitted
Z = atomic number

In Hall - Heroult process, the following is used for reducing Al₂O₃ :-

Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R
Assertion A : Sodium is about 30 times as abundant as potassium in the oceans.
Reason R : Potassium is bigger in size than sodium.
In the light of the above statements, choose the correct answer from the options given below

Which of these reactions is not a part of breakdown of ozone in stratosphere?

The correct order of reactivity of following haloarenes towards nucleophilic substitution with aqueous NaOH is 

Choose the correct answer from the options given below:

The descending order of acidity for the following carboxylic acid is-
A. CH₃COOH
B. F₃C-COOH
C. CICH₂-COOH
D. FCH₂-COOH
E. BrCH₂-COOH
Choose the correct answer from the options given below:

The product (P) formed from the following multistep reaction is:

Match List l with List ll.

List I Natural amino acid	List II One letter code
(I) Glutamic acid	(a) Q
(II) Glutamine	(b) W
(III) Tyrosine	(c) E
(IV) Tryptophan	(d) Y

Choose the correct answer from the options given below:

Given below are two statements:
Statement I: In redox titration, the indicators used are sensitive to change in pH of the solution.
Statement II: In acid-base titration, the indicators used are sensitive to change in oxidation potential.
In the light of the above statements, choose the most appropriate answer from the options given below

The number of species from the following carrying a single lone pair on central atom Xenon is ______ .
XeF₅⁺, XeO₃, XeO₂F₂, XeF₅^-, XeO₃F₂, XeOF₄, XeF₄

For complete combustion of ethene,
\(C_2H_4(g) + 3O_2(g) \longrightarrow 2CO_2(g) + 2H_2O (l)\)
the amount of heat produced as measured in bomb calorimeter is 1406 kJ mol^-1 at 300K. The minimum value of \(T\Delta S\) needed to reach equilibrium is (-) _____ . kJ.(Nearest integer)
Given: R = 8.3 J K^-1 mol^-1

If the boiling points of two solvents X and Y (having same molecular weights) are in the ratio 2:1 and their enthalpy of vaporizations are in the ratio 1:2, then the boiling point elevation constant of X is m times the boiling point elevation constant of Y. The value of m is ______ (nearest integer).

The number of incorrect statements from the following is _____
A. The electrical work that a reaction can perform at constant pressure and temperature is equal to the reaction Gibbs energy.
B. E°_cell is dependent on the pressure.
C. dE^θ cell/dT = Δ_rS^θ/nF
D. A cell is operating reversibly if the cell potential is exactly balanced by an opposing source of potential difference.

Coagulating value of the electrolytes AlCl₃ and NaCl for As₂S₃ are 0.09 and 50.04 respectively. The coagulating power of AlCl₃ is x times the coagulating power of NaCl. The value of x is ______ .

Match List I with List II :

	List I		List II
A	3 Translational degrees of freedom	I	Monoatomic gases
B	3 Translational, 2 rotational degrees of freedoms	II	Polyatomic gases
C	3 Translational, 2 rotational and 1 vibrational degrees of freedom	III	Rigid diatomic gases
D	3 Translational, 3 rotational and more than one vibrational degrees of freedom	IV	Nonrigid diatomic gases

Choose the correct answer from the options given below:

Given below are two statements:  
Statement I : Pressure in a reservoir of water is same at all points at the same level of water.  
Statement II : The pressure applied to enclosed water is transmitted in all directions equally. 
In the light of the above statements, choose the correct answer from the options given below : 

The position-time graphs for two students A and B returning from school to their homes are shown in the figure.

A. A lives closer to the school
B. B lives closer to the school
C. A takes lesser time to reach home
D. A travels faster than B
E. B travels faster than A
Choose the correct answer from the options given below :

A carrier wave of amplitude 15 V modulated by a sinusoidal base band signal of amplitude 3 V. The ratio of maximum amplitude to minimum amplitude in an amplitude modulated wave is

A zener diode of power rating 1.6 W is used as a voltage regula tor. If the zener diode has a breakdown voltage of 8 V and it has to regulate voltage fluctuating between 3 V and 10 V, what is the value of resistance Rs for safe operation of the diode?