List of top Physics Questions asked in JEE Main

A particle starts from origin $O$ from rest and moves with a uniform acceleration along the positive $x$-axis. Identify all figures that correctly represent the motion qualitatively. (a = acceleration, v = velocity, x = displacement, t = time)

A passenger train of length $60\,m$ travels at a speed of $80\, km/hr$. Another freight train of length $120\, m$ travels at a speed of $30\, km/hr$. The ratio of times taken by the passenger train to completely cross the freight train when : (i) they are moving in the same direction, and (ii) in the opposite directions is :

Two particles are projected from the same point with the same speed $u$ such that they have the same range $R$, but different maximum heights, $h_1$ and $h_2$. Which of the following is correct ?

A plane is inclined at an angle $\alpha = 30^{\circ}$ with a respect to the horizontal. A particle is projected with a speed $u = 2 ms^{-1}$ from the base of the plane, making an angle $q = 15^{\circ}$ with respect to the plane as shown in the figure. The distance from the base, at which the particle hits the plane is close to : (Take $g = 10 \; ms^{-2}$)

The magnetic field of an electromagnetic wave is given by : $\vec{B} =1.6 \times10^{-6} \cos\left(2\times10^{7} z +6 \times10^{15}t\right)\left(2\hat{i} +\hat{j}\right) \frac{Wb}{m^{2}} $ The associated electric field will be :-

A $27\, mW$ laser beam has a cross-sectional area of $10 \; mm^2$. The magnitude of the maximum electric field in this electromagnetic wave is given by [Given permittivity of space $\in_0 = 9 \times 10^{-12} $ SI units, Speed of light $c = 3 \times 10^8 \; m/s$] :

A plane electromagnetic wave travels in free space along the x-direction. The electric field component of the wave at a particular point of space and time is $E = 6 \; V \; m^{-1}$ along y-direction. Its corresponding magnetic field component, B would be :

The magnitude of the magnetic field at the center of an equilateral triangular loop of side $1\,m$ which is carrying a current of $10\, A$ is : [Take $\mu_0 = 4\pi \times 10^{-7} \; NA^{-2}]$

If surface tension (S), Moment of inertia (I) and Planck's constant (h), were to be taken as the fundamental units, the dimensional formula for linear momentum would be : -

A person standing on an open ground hears the sound of a jet aeroplane, coming from north at an angle $60^\circ$ with ground level. But he finds the aeroplane right vertically above his position. If $\upsilon$ is the speed of sound, speed of the plane is :

In a car race on straight road, car $A$ takes a time $t$ less than car $B$ at the finish and passes finishing point with a speed $'v'$ more than that of car $B$. Both the cars start from rest and travel with constant acceleration $a_1$ and $a_2$ respectively. Then $'v'$ is equal to :

In the cube of side $'a'$ shown in the figure, the vector from the central point of the face $ABOD$ to the central point of the face $BEFO$ will be:

Two vectors $\vec{A}$ and $\vec{B}$ have equal magnitudes. The magnitude of $(\vec{A} + \vec{B})$ is 'n' times the magnitude of $(\vec{A} - \vec{B})$ . The angle between $\vec{A}$ and $\vec{B}$ is :

Condiser the nuclear fission ${Ne^{20} -> 2 He^{4} + C^{12}} $ Given that the binding energy/nucleon of ${Ne^{20}, He^{4}}$ and ${C^{12}}$ are, respectively, 8.03 MeV, 7.07 MeV and 7.86 MeV, identify the correct statement :

Two radioactive materials $A$ and $B$ have decay constants $10 \lambda$ and $\lambda$, respectively. It initially they have the same number of nuclei, then the ratio of the number of nuclei of $A$ to that of $B$ will be $1/e$ after a time :

The ratio of mass densities of nuclei of $^{40}C_a$ and $^{16}O$ is close to :-

A sample of radioactive material $A$, that has an activity of $10 \; mCi (1 \; Ci = 3.7 \times 10^{10}$ decays/s), has twice the number of nuclei as another sample of a different radioactive maternal $B$ which has an activity of $20\, mCi$. The correct choices for hall-lives of $A$ and $B$ would then be respectively :

Consider an electron in a hydrogen atom, revolving in its second excited state (having radius $4.65\,?$). The de-Broglie wavelength of this electron is :

In a hydrogen like atom, when an electron jumps from the $M$ - shell to the $L$ - shell, the wavelength of emitted radiation is $\lambda$. If an electron jumps from $N$-shell to the $L$-shell, the wavelength of emitted radiation will be :

In $Li^{++}$, electron in first Bohr orbit is excited to a level by a radiation of wavelength $\lambda$. when the ion gets deexcited to the ground state in all possible ways (including intermediate emissions), a total of six spectral lines are observed. What is the value of $\lambda$ ? (Given : $h = 6.63 \times 10^{-34} \; Js ; c = 3 \times 10^8 \; ms^{-1})$ ;

A plano-convex lens (focal length $f_2$, refractive index $\mu_2$, radius of curvature $R$) fits exactly into a plano-concave lens (focal length $f_1$, refractive index $\mu_2$, radius of curvature R). Their plane surfaces are parallel to each other. Then, the focal length of the combination will be :

A plano convex lens of refractive index $\mu_1$ and focal length $f_1$ is kept in contact with another plano concave lens of refractive index $\mu_2$ and focal length $f_2$. If the radius of curvature of their spherical faces is R each and $f_1 = 2f_2$, then $\mu_1$ and $\mu_2$ are related as :

In an interference experiment the ratio of amplitudes of coherent waves is $\frac{a_1}{a_2} = \frac{1}{3}$ . The ratio of maximum and minimum intensities of fringes will be :

What is the position and nature of image formed by lens combination shown in figure? $(f_1, f_2$ are focal lengths)

One plano-convex and one plano-concave lens of same radius of curvature $'R'$ but of different materials are joined side by side as shown in the figure. If the refractive index of the material of $1$ is $\mu_1$ and that of $2$ is $\mu_2$, then the focal length of the combination is :