List of top Physics Questions

A certain vector in the $x y$ plane has an $x$-component of $12\, m$ and a $y$-component of $8\, m$. It is then rotated in the $x-y$ plane so that its $x$-component is halved. Then ifs new $y$-component is approximately

Which of the two (i) compressing a gas isothermally until its volume is reduced by half (ii) compressing the same gas adiabatically until its volume is reduced by half, will require more work to be done?

Water is flowing through a very narrow tube. The velocity of water below which the flow remains a streamline flow is known as

A particle executes simple harmonic motion with amplitude A. The distance moved by the particle in one oscillation is

The current in a coil changes from 1 mA to 5 mA in 4 ms. ? If the coefficient of self-inductance of the 'coil is 10 mH,. the magnitude of "self-induced" emf is?

A block of mass 0.1 kg is held against a wall by applying a horizontal force of 5 N on it. If $\mu,$ between the wall? and the block is 0.5, the magnitude of the frictional force acting on the block is

A ring rolls down an inclined plane. The ratio of rotational kinetic energy to translational kinetic energy is

If $x =at + bt^2$ where $x$ is measured in m and t ins, thenthe dimension of (b/a) is

A mass of 0.1 kg is hung at the 20 cm mark from a 1 m rod weighing 0.25 kg pivoted at its centre. The rod will not topple if

A particle is moving eastward with velocity $5 \, m \, s^{-1}$ In 10 s the velocity changes to $5\, m\, s^{-1}$ northwards. The average acceleration in this time is

Two point charges $Q_1 = 2 \mu C$ and $ Q_2 = 1 \mu C$ are placed as shown. The coordinates of the point P are (2 cm, 1 cm). The electric intensity vector at P subtends an angle $\theta$ with the positive X-axis. The value of $\theta$ is given by

In the case of the Bohr atom model, if $E_k$ and $U$ are the kinetic and potential energies of an electron in an orbit then,

A glass hemisphere of radius 0.1 cm and refractive index 1.5 is placed over a spot on a table and the spot is viewed from above. The spot appears to be

The layer in earth's atmosphere which reflects radio waves from the earth thus, helping radio communication is

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?

$C$ 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 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

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 :