List of top Physics Questions

The position vector of a particle is given by $\vec{x}=(t^{3}-3t^{2}+2)\hat{i}$, the time at which the velocity of the moving particle becomes zero is

A non-conservative force is one for which

The area under the velocity-time graph of a particle is equal to its

If the time period of oscillation of a liquid drop is given by $T=k\sqrt{\frac{\rho r^{4}}{\sigma}}$, where $\rho$ refers to its density, $r$ its radius and $k$ is a dimensionless constant, then $\sigma$ has the units of

The dimensional formula for the rate of change of momentum of a moving body is

If both x and y components of a vector are equal, its angle with x-axis is

A $250$ watt bulb emits monochromatic light of wavelength $198.78$ nm. How many photons are emitted by the bulb per second? \ (Planck’s constant = $6.626 \times 10^{-34}$ J s and velocity of light = $3 \times 10^8$ ms$^{-1}$)

The rate of fall of the voltage across the capacitor in a filter used in a diode rectifier depends

The radius of innermost orbit of an electron in the hydrogen atom is $0.53\,\text{\AA}$. Then, the radius of the 3rd electron orbit is:

The energy released by $2.35\,g$ of $^{235}U$ by fission in a nuclear reactor (in $MeV$) is (Average energy released per fission is $200\,MeV$):

In a silicon crystal containing $N$ atoms, at absolute zero the $4N$ energy states of

A wire of certain length carrying current $I$, when bent into a circular coil of single turn produces a magnetic field $B$ at its centre. If the same wire is bent into a circular coil of 3 turns and it carries the same current, then the magnetic field at the centre of the coil is

The intensity of the transmitted light after passing through a first polaroid $P_1$ is $I_0$. If the second polaroid $P_2$ is rotated through an angle of $45^\circ$ with respect to $P_1$, then the change in the intensity of the transmitted light after passing through the second polaroid is

The order of the electric field required to pull out electrons from a metal by field emission (in $Vm^{-1}$) is

The magnifying power of a simple microscope can be increased by using

When a bar magnet placed parallel to the magnetic field is rotated by $45^\circ$, the amount of work done is $2.07J$. The amount of work to be done to rotate the magnet further by $45^\circ$ is

A real object is placed at distance $f$ in front of a convex mirror of focal length $f$. The image will be formed at a distance

The law that is a symmetrical counterpart of Faraday’s law of electromagnetic induction is

The r.m.s current of an alternating current given by $i = 4\sqrt{2}\sin \omega t + 3\sqrt{2}\cos \omega t$ is:

If an air core solenoid with self-inductance of $0.5\,mH$ is filled with soft iron of relative permeability of $1500$, its self-inductance becomes

For an electron of mass $m_e$ and charge $e$ revolving around the nucleus of an atom, the ratio of its angular momentum to magnetic moment is

Two charged particles $2q$ and $q$ having equal momentum enter a uniform magnetic field in a direction perpendicular to the magnetic field. Then their respective radii of circular paths $r_1$ and $r_2$ are in the ratio

Two cells each of $2V$ and internal resistance $0.1\,\Omega$ are connected in parallel combination. This combination is equivalent to a single cell with emf and internal resistance of

If a spherical conductor of $10\,cm$ radius contains $5 \times 10^6$ electrons, then the electric field on its surface (in $NC^{-1}$) is

In the equation $A = \dfrac{B}{CD^2}$, if $B, C$ and $D$ have the dimensions of inductive reactance, capacitive reactance and angular frequency respectively, then the dimensions of $A$ are: