List of top Physics Questions

One mole of a monatomic ideal gas undergoes a transformation from an initial state with temperature $290\text{ K}$ and volume $30\text{ litres}$ to a final state with temperature $310\text{ K}$ and volume $16\text{ litres}$. On the pressure–volume ($P - V$) diagram, this process is represented by a straight line path. The magnitude of the work done (in joules) during this process is close to

A sphere made of a material with density $12\text{ kg}\cdot\text{m}^{-3}$ and weighing $100\text{ N}$ in vacuum is immersed in a container of gas. Its weight in gas is $85\text{ N}$. The density of the gas in $\text{kg}\cdot\text{m}^{-3}$ is closest to

An infinitely long straight wire with uniform line charge density $\lambda$ lies at a perpendicular distance $d$ from a point O. The total electric flux through the surface of a sphere of radius $R \gt d$ centred at O, is

Let $A$ be the mass number, $Z$ be the atomic number and $N$ be the neutron number of a nucleus. Then the statement which is always true, is

A spherical glass bottle having negligible wall thickness is placed in air. When the bottle is completely filled with water, its focal length is $f$. If the water is replaced by another transparent liquid of higher refractive index, then the focal length changes to $f'$. Then

Ice on land mass melting into ocean, due to global warming, is estimated to be around $1.3 \times 10^{15}\text{ kg}$ per year. The density of sea water is $1025\text{ kg}\cdot\text{m}^{-3}$. Assuming that the melting rate of ice remains constant and the effective surface area covered by the oceans is $3.6 \times 10^{14}\text{ m}^2$, the estimated average rise in sea level (in m) in the next 75 years will be closest to

Two wave pulses, one rectangular and other triangular, approach each other as shown in the figure below.

They overlap at the point P at time $t$. The diagram best representing the appearance of the wave pulses at a time $t' \gt t$ is

Physicist Luis Alvarez and his collaborators hypothesised that the extinction of dinosaurs was due to the impact of an asteroid with the Earth. They estimated the mass and the radius of the asteroid to be about $2 \times 10^{15}\text{ kg}$ and $10\text{ km}$ respectively. Take the mass of the Earth to be $6 \times 10^{24}\text{ kg}$. The gravitational acceleration (in SI units) of the Earth due to the asteroid just before the impact would be of the order

The angular speed of the Earth’s rotation is $7.3 \times 10^{-5}\text{ rad}\cdot\text{s}^{-1}$. Take the radius of the Earth at the equator to be $6400\text{ km}$. Then the ratio ($a_c / g$) of the magnitude of the centripetal acceleration $a_c$ at a point on the equator to $g$, is of the order

An electromagnetic wave travels from vacuum into a non-magnetic dielectric medium with permittivity $\epsilon = 4\epsilon_0$. If the ratio ($E_0 / B_0$) of the electric field amplitude $E_0$ to the magnetic field amplitude $B_0$ in vacuum is equal to the speed of light $c$, then the corresponding ratio in the given medium is

Among the following, the waves responsible for energy transfer in vacuum are

A ray of light MN is incident normally on the face corresponding with side AB of a prism with an isosceles right-angled triangular base ABC. Trace the path of the ray as it passes through the prism when the refractive index of the prism material is \( \sqrt{2} \), and \( \sqrt{3} \).

A particle moves in a circle of radius \(R\) with a constant speed \(v\). The magnitude of the change in velocity after the particle has traveled half of the circular path is:

In Young's double-slit experiment, if the separation between the slits is halved and the distance between the slits and the screen is doubled, the fringe width will be:

The work function of a metal is \(4.0\text{ eV}\). If the metal is irradiated with radiation of wavelength \(200\text{ nm}\), the maximum kinetic energy of the photoelectrons would be about:
(Use \(hc = 1240\text{ eV}\cdot\text{nm}\))

A point charge \(q\) is placed at a distance \(a/2\) directly above the center of a square of side \(a\). The electric flux through the square is:

Two wires of the same material have lengths in the ratio \(1 : 2\) and radii in the ratio \(1 : 2\). The ratio of their specific resistances will be:

An ac circuit contains a resistance of 1 k$\Omega$, a capacitor of 0.1 $\mu$F and an inductor of 1 mH connected in series. The resonance frequency of the circuit is approximately: ____.

If the nuclear force between a proton and a neutron is attractive, then the distance between them can be:

The magnetic field at a point A on the axis of a short bar magnet is $1500\%$ more than the magnetic field at a point B on the normal bisector of the magnet. If the distance of point A from the centre of the magnet is $18\text{ cm}$, then the distance of point B from the centre of the magnet is:

If a conducting rod of length $100\text{ cm}$ rotates about one of its ends with a constant frequency of $14\text{ revolutions per second}$ in a plane perpendicular to a uniform magnetic field of $2\text{ T}$, then the induced emf between the two ends of the rod is:

If a plane electromagnetic wave of intensity $9 \times 10^5\text{ W}\cdot\text{m}^{-2}$ incidents normally on a perfectly absorbing surface of area $2\text{ m}^2$ for a time of $180\text{ s}$, then the average force exerted by the electromagnetic wave on the surface during this time is:

If the wavelength of a spectral line in the Balmer series of hydrogen spectrum is $\frac{7.2}{R}$, then the ratio of the radii of the higher and lower orbits between which the transition of electron takes place is ($R$ - Rydberg constant):

When an inductor is connected to a $200\text{ V}$ dc supply, the current through it is $5\text{ A}$ and when the same inductor is connected to a $200\text{ V}$ ac supply of angular frequency $300\text{ rad s}^{-1}$, the current through it is $4\text{ A}$. The inductance of the inductor is: