List of top Physics Questions

The ratio of speed of sound in Hydrogen to that in Oxygen at the same temperature is

The carrier of electromagnetic interaction is

"Plum pudding" model of an atom was proposed by

According to Faraday's law of electromagnetic induction, an emf is induced in a coil if

Consider a thin spherical shell of radius $R$ with its centre at the origin, carrying uniform positive surface charge density. The variation of the magnitude of the electric field and the electric potential $V (r)$ with the distance $r$ from the centre, is best represented by which graph?

A parallel plate capacitor has a uniform electric field E in the space between the plates. If the distance between the plates is d and area of each plate is A, the eneigy stored in the capacitor is

$C$ and $Si$ both have same lattice structure; having $4$ bonding electrons in each. However, $C$ is insulator where as $Si$ is intrinsic semiconductor. This is because

A proton carrying 1 MeV kinetic energy is moving in a circular path of radius R in uniform magnetic field. What should be the energy of an $\alpha$-particle to describe a circle of same radius in the same field?

A slab of stone of area 0.36 m2 and thickness 0.1 m is exposed on the lower surface to steam at 100$^{\circ}$C. A block of ice at 0$^{\circ}$C rests on the upper surface of the slab. In one hour 4.8 kg of ice is melted. The thermal conductivity of slab is (Given latent heat of fusion of ice = $ 3.36 \times 10^5 J kg^{-1})$

The electric field associated with an e. $m$. wave in vacuum is given by $\vec{ E }=\hat{ i } 40 \cos \left( kz -6 \times 10^{8} t \right)$, where $E , z$ and $t$ are in volt $/ m$, meter and seconds respectively. The value of wave vector $k$ is :

An $\alpha -$ particle moves in a circular path of radius $0.83\, cm$ in the presence of a magnetic field of $0.25\, Wb/m^2. $ The de Broglie wavelength associated with the particle will be (Take $h = 6.63 ? 10^{-34} J\, s$, $e =1.6 ?10^{-19}C$)

The height at which the weight of a body becomes $1 / 16^{\text {th }}$, its weight on the surface of earth (radius R), is

A particle has initial velocity $ ( 2 \vec{i} + 3 \vec{j})$ and acceleartion ($ 0 . 3 \vec{i} + 0 . 2 \vec{j})$ The magnitude of velocity after 10 seconds will be

A geostationary satellite is orbiting the earth at a height of $5\,R$ above that surface of the earth, $R$ being the radius of the earth. The time period of another satellite in hours at a height of $2\,R$ from the surface of the earth is

A train moving at a speed of $220\,ms^{-1}$ towards a stationary object, emits a sound of frequency $1000\, Hz$. Some of the sound reaching the object gets reflected back to the train as echo. The frequency of the echo as detected by the driver of the train is (Speed of sound in air is $330\,ms^{-1}$)

A milli voltmeter of $25$ milli volt range is to be converted into an ammeter of $25$ ampere range. The value (in ohm) of necessary shunt will be

A spherical planet has a mass $M_p$ and diameter $D_p$. A particle of mass $m$ falling freely near the surface of this planet will experience an acceleration due to gravity, equal to

To get the maximum flight, a ball must be thrown as

An electron of a stationary hydrogen atom passes from the fifth energy level to the ground level. The velocity that the atom acquired as a result of photon emission will be ($m$ is the mass of the electron, $R$, Rydberg constant and $h$ Planck's constant)

A magnetic needle suspended parallel to a magnetic field requires $\sqrt 3 \,J$ of work to turn it through $60^\circ.$ The torque needed to maintain the needle in this position will be

Electron in hydrogen atom first jumps from third excited state to second excited state and then from second excited to the first excited state.
The ratio of the wavelengths \(\lambda_1 : \lambda_2\) emitted in the two cases is:

An electron and a proton, both having the same kinetic energy, enter a region of uniform magnetic field, in a plane perpendicular to the field. If their masses are denoted by $m_{e}$ and $m_{p}$ respectively, then the ratio of the radii (electron to proton) of their circular orbits is

Which of the following is the correct Kirchhoff's loop rule?

What is the resonance frequency of a driven $LCR$ oscillator?

A cheetah, weighing $150 \,kg$, chases a deer, weighing $30 \, kg$, in a straight path. The speed of the cheetah is $20 \,m / s$ and that of the deer is $25 m / s$. The approximate speed of the centre of mass of the pair is