JEE Main 2024 Physics Paper: 29 Jan, Shift 2

In an a.c. circuit, voltage and current are given by:

$V = 100\sin(100t)\text{ V}$ and $I = 100\sin\left(100t + \frac{\pi}{3}\right)\text{ mA}$ respectively.

The average power dissipated in one cycle is:

Given below are two statements:

Statement I: Most of the mass of the atom and all its positive charge are concentrated in a tiny nucleus and the electrons revolve around it, is Rutherford's model.

Statement II: An atom is a spherical cloud of positive charges with electrons embedded in it, is a special case of Rutherford's model.

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

Hydrogen atom is bombarded with electrons accelerated through a potential difference of $V$, which causes excitation of hydrogen atoms. If the experiment is being performed at $T = 0\text{ K}$, the minimum potential difference needed to observe any Balmer series lines in the emission spectra will be $\frac{\alpha}{10}\text{ V}$, where $\alpha =$ __________.

In the given figure, the charge stored in $6\ \mu\text{F}$ capacitor, when points $A$ and $B$ are joined by a connecting wire is __________ $\mu\text{C}$.

A particle is moving in a circle of radius $50\text{ cm}$ in such a way that at any instant the normal and tangential components of it's acceleration are equal. If its speed at $t = 0$ is $4\text{ m/s}$, the time taken to complete the first revolution will be $\frac{1}{\alpha}\left[1 - e^{-2\pi}\right]\text{ s}$, where $\alpha =$ _________.

A stone of mass $900\text{ g}$ is tied to a string and moved in a vertical circle of radius $1\text{ m}$ making $10\text{ rpm}$. The tension in the string, when the stone is at the lowest point is (if $\pi^2 = 9.8$ and $g = 9.8\text{ m/s}^2$):

In the given circuit, the current in resistance R${}_{3}$ is:

In the given circuit, the current flowing through the resistance $20\ \Omega$ is $0.3\text{ A}$, while the ammeter reads $0.9\text{ A}$. The value of $R_1$ is _________ $\Omega$.

Two sources of light emit with a power of $200\text{ W}$. The ratio of number of photons of visible light emitted by each source having wavelengths $300\text{ nm}$ and $500\text{ nm}$ respectively, will be:

A horizontal straight wire $5\text{ m}$ long extending from east to west is falling freely at right angle to horizontal component of earths magnetic field $0.60 \times 10^{-4}\text{ Wb m}^{-2}$. The instantaneous value of emf induced in the wire when its velocity is $10\text{ ms}^{-1}$ is _________ $\times 10^{-3}\text{ V}$.

A plane electromagnetic wave of frequency $35\text{ MHz}$ travels in free space along the $x$-direction. At a particular point (in space and time) $\vec{E} = 9.6\hat{j}\text{ V/m}$. The value of magnetic field at this point is:

An electric field is given by $(6\hat{i} + 5\hat{j} + 3\hat{k})\text{ N/C}$. The electric flux through a surface area $30\hat{i}\text{ m}^2$ lying in YZ-plane (in SI unit) is:

A planet takes 200 days to complete one revolution around the Sun. If the distance of the planet from Sun is reduced to one fourth of the original distance, how many days will it take to complete one revolution:

A wire of length $L$ and radius $r$ is clamped at one end. If its other end is pulled by a force $F$, its length increases by $l$. If the radius of the wire and the applied force both are reduced to half of their original values keeping original length constant, the increase in length will become:

Two metallic wires $P$ and $Q$ have same volume and are made up of same material. If their area of cross sections are in the ratio $4 : 1$ and force $F_1$ is applied to $P$, an extension of $\Delta l$ is produced. The force which is required to produce same extension in $Q$ is $F_2$.

The value of $\frac{F_1}{F_2}$ is _________.

A particle is moving in a straight line. The variation of position '$x$' as a function of time '$t$' is given as $x = \left(t^3 - 6t^2 + 20t + 15\right)\text{ m}$. The velocity of the body when its acceleration becomes zero is:

A charge of $4.0\ \mu\text{C}$ is moving with a velocity of $4.0 \times 10^{6}\text{ ms}^{-1}$ along the positive $y$ axis under a magnetic field $\vec{B}$ of strength $(2\hat{k})\text{ T}$. The force acting on the charge is $x\hat{i}N$. The value of $x$ is __________.

Two particles $X$ and $Y$ having equal charges are being accelerated through the same potential difference. Thereafter they enter normally in a region of uniform magnetic field and describe circular paths of radii $R_1$ and $R_2$ respectively. The mass ratio of $X$ and $Y$ is:

A simple harmonic oscillator has an amplitude $A$ and time period $6\pi$ second. Assuming the oscillation starts from its mean position, the time required by it to travel from $x =$ A to $x = \frac{\sqrt{3}}{2}$ A will be $\frac{\pi}{x}\text{ s}$, where $x =$ _________.

The bob of a pendulum was released from a horizontal position. The length of the pendulum is $10\text{ m}$. If it dissipates $10\%$ of its initial energy against air resistance, the speed with which the bob arrives at the lowest point is:

[Use, $g : 10\text{ m s}^{-2}$]

If the distance between object and its two times magnified virtual image produced by a curved mirror is $15\text{ cm}$, the focal length of the mirror must be:

A body of mass $5\text{ kg}$ moving with a uniform speed $3\sqrt{2}\text{ ms}^{-1}$ in $X - Y$ plane along the line $y = x + 4$. The angular momentum of the particle about the origin will be _________ $\text{kg m}^{2}\ \text{s}^{-1}$.

The truth table for this given circuit is:

A small liquid drop of radius $R$ is divided into 27 identical liquid drops. If the surface tension is $T$, then the work done in the process will be:

$N$ moles of a polyatomic gas $(f = 6)$ must be mixed with two moles of a monoatomic gas so that the mixture behaves as a diatomic gas. The value of $N$ is:

The temperature of a gas having $2.0 \times 10^{25}$ molecules per cubic meter at $1.38\text{ atm}$ (Given, $k = 1.38 \times 10^{-23}\text{ J K}^{-1}$) is:

A physical quantity $Q$ is found to depend on quantities $a, b, c$ by the relation $Q = \frac{a^4b^3}{c^2}$. The percentage error in $a, b$ and $c$ are $3\%, 4\%$ and $5\%$ respectively. Then, the percentage error in $Q$ is:

In a single slit diffraction pattern, a light of wavelength 6000$\text{\AA}$ is used. The distance between the first and third minima in the diffraction pattern is found to be $3\text{ mm}$ when the screen in placed $50\text{ cm}$ away from slits. The width of the slit is _________ $\times 10^{-4}\text{ m}$.

In Young's double slit experiment, light from two identical sources are superimposing on a screen. The path difference between the two lights reaching at a point on the screen is $7\lambda/4$. The ratio of intensity of fringe at this point with respect to the maximum intensity of the fringe is: