List of top Questions asked in JEE Main

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

Assertion (A) : The beam of electrons show wave nature and exhibit interference and diffraction

Reason (R) : Davisson Germer Experimentally verified the wave nature of electrons

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

Molar mass of the hydrocarbon (X) which on ozonolysis consumes one mole of O3 per mole of (X) and gives one mole each of ethanal and propanone is _______ g mol-1
(Molar mass of C : 12 g mol-1 , H : 1 g mol-1)

A bowl filled with very hot soup cools from $98^{\circ} C$ to $86^{\circ} C$ in 2 minutes when the room temperature is $22^{\circ} C$. How long it will take to cool from $75^{\circ} C$ to $69^{\circ} C$ ?

A bar magnet with a magnetic moment 50 $Am ^2$ is placed in parallel position relative to a magnetic field of 0.4T. The amount of required work done in turning the magnet from parallel to antiparallel position relative to the field direction is

The integral $∫^∞_0 \frac{6}{(e^{3x} + 6e^{2x} + 11e{x} + 6)}dx$

A closed circular tube of average radius 15 cm, whose inner walls are rough, is kept in vertical plane. A block of mass 1 kg just fit inside the tube. The speed of block is 22 m/s, when it is introduced at the top of tube. After completing five oscillations, the block stops at the bottom region of tube. The work done by the tube on the block is J. (Given: g = 10 ms⁻²)

A solenoid of $1200$ tums is wound uniformly in a single layer on a glass tube $2\, m$ long and $02\, m$ in diameter The magnetic intensity at the center of the solenoid when a current of $2 A$ flows through it is:

$max\\{0≤x≤π}$ $\{x−2\,\, sin. x \,\,cos+\frac{1}{3} sin\,\, 3x \}=$

The titration curve of weak acid vs. strong base with phenolphthalein as indictor is shown below. The K_{phenolphthalein} = 4 × 10^-10 .
Given: log2 = 0.3

The number of following statements which is/are correct about phenolphthalein is______
A. It can be used as an indicator for the titration of weak acid with weak base.
B. It begins to change colour at pH = 8.4
C. It is a weak organic base
D. It is colourless in acidic medium.

The amplitude of $15 \sin (1000 \pi t )$ is modulated by $10 \sin (4 \pi t )$ signal The amplitude modulated signal contains frequency (ies) of
A $500\,Hz$
B $2\, Hz$
C $250\, Hz$
D $498\, Hz$
E $502\, Hz$
Choose the correct answer from the options given below:

The initial speed of a projectile fired from ground is $u$ At the highest point during its motion, the speed of projectile is $\frac{\sqrt{3}}{2} u$ The time of flight of the projectile is :

If 1000 droplets of water of surface tension 0.07 N/m, having same radius 1 mm each, combine to from a single drop In the process the released surface energy is - (Take π=$\frac {22}{7}$)

Let a =$\^i+4\^j+2\^k,b=3\^i−2\^j+7\^k \,\,\,\,and\,\,\.\ c=2\^i−\^j+4\^k$. Find a vector d satisfies $\overrightarrow{d}\times{\overrightarrow{b}}=\overrightarrow{c}\times{\overrightarrow{b}}$ and $\overrightarrow{d}.\overrightarrow{a}=24$, then $|\overrightarrow{d}|^2$ is equal to

In Young's double slits experiment, the position of $5^{\text {th }}$ bright fringe from the central maximum is $5 \,cm$ The distance between slits and screen is $1 \,m$ and wavelength of used monochromatic light is $600 \,mm$ The separation between the slits is:

The number of following statement/s which is/are$\text{\underline{ incorrect}}$ is______
(A) Line emission spectra are used to study the electronic structure
(B) The emission spectra of atoms in the gas phase show a continuous spread of wavelength from red to violet
(C) An absorption spectrum is like the photographic negative of an emission spectrum
(D) The element helium was discovered in the sun by spectroscopic method.

An electromagnetic wave is transporting energy in the negative $z$ direction At a certain point and certain time the direction of electric field of the wave is along positive $y$ direction What will be the direction of the magnetic field of the wave at that point and instant?

Three bulbs are filled with CH4, CO2 and Ne as shown in the picture. The bulbs are connected through pipes of zero volume. When the stopcocks are opened and the temperature is kept constant throughout, the pressure of the system is found to be_______atm. (Nearest integer)

A message signal of frequency $5 \,kHz$ is used to modulate a carrier signal of frequency $2\, MHz$ The bandwidth for amplitude modulation is:

In chromyl chloride, the number of d-electrons present on chromium is same as in (Given at no. of Ti : 22, V : 23, Cr : 24, Mn : 25, Fe : 26)

In an LC oscillator, if values of inductance and capacitance become twice and eight times, respectively, then the resonant frequency of oscillator becomes $x$ times its initial resonant frequency $\omega_0$ The value of $x$ is:

$(S1) : lim_{n→∞}\frac{1}{ n ^2} ( 2 + 4 + 6 + . . . . + 2n) = 1$
$(S2): lim_n→∞\frac{1}{n^{16}}( 1^15 +2^15 +3^15 + . . . . + n^15 ) = \frac{1}{16} $

The root mean square velocity of molecules of gas is

A parallel plate capacitor has plate area $40\, cm ^2$ and plates separation $2\, mm$ The space between the plates is filled with a dielectric medium of a thickness $1 \,mm$ and dielectric constant $5$ The capacitance of the system is :

Let s₁, s₂, s₃,…..,s₁₀ respectively be the sum to 12 terms of 10 A.P.s whose first terms are 1,2,3, …. ,10 and the common differences are 1, 3, 5, …. , 19 respectively. Then $10∑^{10}_{i=1} s_i$ is

Match List-I with List-II :

	List-I		List-II
A	Saccharin	I	High potency sweetener
B	Aspartame	II	First artificial sweetening agent
C	Alitame	III	Stable at cooking temperature
D	Sucralose	IV	Unstable at cooking temperature

Choose the correct answer from the options given below :