JEE MAIN Physics Medium Previous Year Questions

A square lamina $OABC$ of side $10\text{cm}$ is pivoted at $O$. Forces act on the lamina as shown in the figure. If the lamina remains stationary, then the magnitude of $F$ is:

The figure given below shows an LCR series circuit with two switches S1 and S2. When switch S1 is closed keeping S2 open, the phase difference ($\varphi$) between the current and source voltage is $30^{\circ }$ and phase difference is $60^{\circ }$ when S2 is closed keeping S1 open. The value of $(3L_1-L_2)$ is ________ H. The capacitor $C=100\mu \text{F}$ and the source is $v=V_0\sin (300t)$.

The equation of motion of a particle is given by $x=a\sin (50t+\frac{\pi }{3})$ cm. The particle will come to rest at time $t_1$ and it will have zero acceleration at time $t_2$. The $t_1$ and $t_2$ respectively are ________.

Two blocks of masses $2\text{kg}$ and $1\text{kg}$ respectively are tied to the ends of a string which passes over a light frictionless pulley. The masses are held at rest at the same horizontal level and then released. The distance traversed by the centre of mass in $2\text{s}$ is _______ m. (Take $g=10{\text{m/s}}^2$)

In a screw gauge the zero of main scale reference line coincides with the fifth division of the circular scale when two studs are in contact. There are 100 divisions in circular scale and pitch of screw gauge is $0.1\text{mm}$. When diameter of a sphere is measured, the reading of main scale is $5\text{mm}$ and $50^{th}$ division of circular scale coincides with the reference line of main scale. The diameter of sphere is ______ mm.

Dimensions of universal gravitational constant $G$ in terms of Planck's constant ($h$), distance ($L$), mass ($M$) and time ($T$) are _______.

Two resistors of $200\Omega$ and $400\Omega$ are connected in series with a battery of $100$V. A bulb rated at $200$V, $100$W is connected across the $400\Omega$ resistance. The potential drop across the bulb is ______ V.

If a body of mass $1\text{kg}$ falls on the earth from infinity, it attains velocity $(v)$ and kinetic energy $(k)$ on reaching the surface of earth. The values of $v$ and $k$ respectively are ________. (Take radius of earth to be $6400\text{km}$ and $g=9.8{\text{m/s}}^2$.)

One side of an equilateral prism is painted by a transparent material of refractive index $n_2$. The refractive index of prism is $1.6$. The minimum value of $n_2$ required for total internal reflection from painted face is

The surface tension of a soap bubble is 0.03 N/m. The work done in increasing the diameter of bubble from 2 cm to 6 cm is $\alpha \pi \times 10^{-4}$ J. The value of $\alpha$ is _______. (Take $\pi =3.14$)

The binding energy per nucleon of ${}_{83}^{209}\mathrm{Bi}$ is _______ MeV. [Take $m{(}_{83}^{209}\mathrm{Bi})=208.980388\mathrm{u}$, $m_p=1.007825\mathrm{u}$, $m_n=1.008665\mathrm{u}$, $1\mathrm{u}=931\mathrm{MeV}/c^2$ ]

Two point charges $8\mu$C and $-2\mu$C are located at $x=2$cm and $x=4$cm, respectively, on the x-axis. The ratio of electric flux due to these charges through two spheres of radii $3$cm and $5$cm with their centers at the origin is ______.

A mixture of carbon dioxide and oxygen has volume 8310 cm${}^3$, temperature 300 K, pressure 100 kPa and mass 13.2 g. The number of moles of carbon dioxide and oxygen gases in the mixture respectively are _______. (Assume both carbon dioxide and oxygen gases behave like ideal gases) [R = 8.31 J/mol.K]

A particle having charge $10^{-9}\text{C}$ moving in the $x$-$y$ plane is in fields $\mathbf{E}=0.4\hat{j}\text{N/C}$ and $\mathbf{B}=4\times 10^{-3}\hat{k}\text{T}$. It experiences a force of $(4\hat{i}+2\hat{j})\times 10^{-10}\text{N}$. The velocity of the particle at that instant is _______ m/s.

If an air bubble of diameter 2 mm rises steadily through a liquid of density 2000 kg/m${}^3$ at a rate of 0.5 cm/s, then the coefficient of viscosity of liquid is ______ Poise. (Take $g=10$ m/s${}^2$)

A spherical ball of mass 2 kg falls from a height of 10 m and is brought to rest after penetrating 10 cm into sand. The average force exerted by sand on the ball is ______ N. (Take $g=10$ m/s${}^2$)

If $X$ and $Y$ are the inputs, the given circuit works as _______. (Logic gate diagram shown in question image)

An electromagnetic wave travels in free space along the x-direction. At a particular point in space and time, $\vec{B}=2\times 10^{-7}\hat{j}$ T is associated with this wave. The value of corresponding electric field $\vec{E}$ at this point is ______ V/m.

A $0.5\text{kg}$ mass is in contact against the inner wall of a cylindrical drum of radius $4\text{m}$ rotating about its vertical axis. The minimum rotational speed of the drum to enable the mass to remain stuck to the wall (without falling) is $5\text{rad/s}$. The coefficient of friction between the drum's inner wall surface and mass is _______. (Take $g=10{\text{m/s}}^2$)

Two metal plates (A, B) are kept horizontally with separation of $\left(\frac{12}{\pi }\right)$ cm, with plate A on the top. An atomizer jet sprays oil (density $1.5$g/cm${}^3$) droplets of radius $1$mm horizontally. All oil droplets carry a charge $5$nC. The potentials $V_A$ and $V_B$ are required on plates A and B respectively in order to ensure the droplets do not descend. The values of $V_A$ and $V_B$ are ______. (Neglect the air resistance to the droplets and take $g=10$m/s${}^2$)