List of top Physics Questions asked in JEE Main

A vector \(\vec{A}\) is rotated by a small angle \(\Delta\theta\) radians \(\left(\Delta\theta<<1\right)\) to get a new vector \(\vec{B}.\) In that case \(\left|\vec{B}-\vec{A}\right|\) is :

Given in the figure are two blocks $A$ and $B$ of weight $20\,N$ and $100\,N$, respectively. These are being pressed against a wall by a force $F$ as shown in figure. If the coefficient of friction between the blocks is $0.1$ and between block $B$ and the wall is $0.15$, the frictional force applied by the wall in block $B$ is

The AC voltage across a resistance can be measured using a :

Two long current carrying thin wires, both with current $I$, are held by insulating threads of length $L$ and are in equilibrium as shown in the figure, with threads making an angle $'\theta'$ with the vertical. If wires have mass $\lambda$ per unit length then, the value of $I$ is : ( $g =$ gravitational acceleration)

The period of oscillation of a simple pendulum is $T=2 \pi \sqrt{\frac{L}{g}}$. Measured value of $L$ is $20.0\, cm$ known to $1\, mm$ accuracy and time for $100$ oscillations of the pendulum is found to be $90\, s$ using a wrist watch of $1\, s$ resolution. The accuracy in the determination of $g$ is

A $25\, cm$ long solenoid has radius $2\, cm$ and $500$ total number of turns. It carries a current of $15\, A$. If it is equivalent to a magnet of the same size and magnetization $|\bar{M}|$ (magnetic moment/volume), then $|\bar{M}|$ is :

The de - Broglie wavelength associated with the electron in the $n = 4$ level is :

From a solid sphere of mass $M$ and radius $R$, a spherical portion of radius $\frac{R}{2}$ is removed, as shown in the figure. Taking gravitational potential $V = 0$ at $r = \infty$, the potential at the centre of the cavity thus formed is ($G =$ gravitational constant)

A pendulum made of a uniform wire of cross sectional area $A$ has time period $T$. When an additional mass $M$ is added to its bob, the time period changes to $T_M$. If the Young's modulus of the material of the wire is $Y$ then $\frac{1}{Y}$ is equal to ( $g =$ gravitational acceleration)

A simple harmonic oscillator of angular frequency $2 \,rad \,s^{-1}$ is acted upon by an external force $F= \sin\, t \,N$. If the oscillator is at rest in its equilibrium position at $t\, =\, 0$, its position at later times is proportional to :

Two stones are thrown up simultaneously from the edge of a cliff $240\, m$ high with initial speed of $10\, m/s$ and $40\, m/s$ respectively. Which of the following graph best represents the time variation of relative position of the second stone with respect to the first? (Assume stones do not rebound after hitting the ground and neglect air resistance, take $g=10\, m/s^2$)

A thin convex lens of focal length ' $f'$ is put on a plane mirror as shown in the figure. When an object is kept at a distance ' $a$ ' from the lens-mirror combination, its image is formed at a distance $\frac{a}{3}$ in front of the combination. The value of ' $a$ ' is

In an ideal gas at temperature $T$, the average force that a molecule applies on the walls of a closed container depends on $T$ as $T^q$. A good estimate for $q$ is :

For plane electromagnetic waves propagating in the $z$ direction, which one of the following combination gives the correct possible direction for $\vec{E}$ and $\vec{B}$ field respectively ?

When current in a coil changes from $5 \,A$ to $2 \,A$ in $0.1\, s$, an average voltage of $50\, V$ is produced. The self - inductance of the coil is :

In the given circuit, charge $Q_2 $ on the $2 \mu F $ capacitor changes as $C$ is varied from $1 \mu F $ to $3 \mu F. $ $Q_2 $ as a function of $'C'$ is given properly by (figures are drawn schematically and are not to scale)

A uniformly charged solid sphere of radius $R$ has potential $V _{0}\, 9$ measured with respect to $\infty$ ) on its surface. For this sphere the equipotential surfaces with potentials $\frac{3 V _{0}}{2}$, $\frac{5 V _{0}}{4}, \frac{3 V _{0}}{4}$ and $\frac{ V _{0}}{4}$ have radius $R _{1}, R _{2}, R _{3}$ and $R _{4}$ respectively. Then

In the electric network shown, when no current flows through the $4\, \Omega$ resistor in the arm $EB$, the potential difference between the points $A$ and $D$ will be :

When $5\,V$ potential difference is applied across a wire of length $0.1\,m$, the drift speed of electrons is $2.5\times10^{-4}$ $ms^{-1}$. If the electron density in the wire is $8\times10^{28}\, m^{-3}$ the resistivity of the material is close to

Consider a spherical shell of radius $R$ at temperature $T$. The black body radiation inside it can be considered as an ideal gas of photons with internal energy per unit volume $u=\frac{U}{V} ? T^4$ and pressure $p=\frac{1}{3}\bigg(\frac{U}{V}\bigg)$ If the shell now undergoes an adiabatic expansion, the relation between $T$ and $R$ is

Consider an ideal gas confined in an isolated closed chamber. As the gas undergoes an adiabatic expansion, the average time of collision between molecules increases as $V^q$ , where $V$ is the volume of the gas. The value of $q$ is $\bigg(\gamma =\frac{C_p}{C_v}\bigg)$

A solid body of constant heat capacity $1 \, J/^{\circ}C$ is being heated by keeping it in contact with reservoirs in two ways (i) Sequentially keeping in contact with $2$ reservoirs such that each reservoir supplies same amount of heat. (ii) Sequentially keeping in contact with $8$ reservoirs such that each reservoir supplies same amount of heat. In both the cases, body is brought from initial temperature $100^{\circ}C$ to final temperature $200^{\circ}C$. Entropy change of the body in the two cases respectively, is

As an electron makes a transition from an excited state to the ground state of a hydrogen- like atom/ion

Two coaxial solenoids of different radii carry current $I$ in the same direction. Let $\vec{F}_1$ be the magnetic force on the inner solenoid due to the outer one and $\vec{F}_2$ be the magnetic force on the outer solenoid due to the inner one. Then,

A long cylindrical shell carries positive surface charge $\sigma$ in the upper half and negative surface charge $-\sigma$ in the lower half. The electric field lines around the cylinder will look like figure given in: (figures are schematic and not drawn to scale)