List of top Physics Questions

When two sinusoidal waves moving at right angle to each other superimpose, they produce

The volume of mercury in the bulb of a thermometer is $ {{10}^{-6}}{{m}^{3}} $ . The area of cross- section of the capillary tube is $ 2\times {{10}^{-7}}{{m}^{2}}. $ If the temperature is raised by $ 100{}^\circ C $ , the increase in the length of the mercury column is $ \left( {{\gamma }_{Hg}}=18\,\times \,{{10}^{-5}}{{/}^{0}}C \right) $

When a glass lens with n = 1.47 is immersed in a trough of liquid, it looks to be disappeared. The liquid in the trough could be

It is difficult to cook rice in an open vessel by boiling it at high altitudes because of

Resistance of tungsten wire at 150$^{\circ}$C is $133 \Omega$. Its resistance temperature coefficient is $0.0045^{\circ}$C. The resistance of the wire at 500$^{\circ}$C will be

The current flowing through a wire depends on time as $I=3t^{2}+2t +5.$ The charge flowing through the cross section of the wire in time from $t = 0$ to $t = 2$ sec. is

Two identical cells each of emf $E$ and internal resistance $r$ are connected in parallel with an external resistance $R$. To get maximum power developed across $R$, the value of $R$ is

The electric field part of an electromagnetic wave in a medium is represented by: $E _{ x }=0$ $E _{ y }=2.5 \frac{ N }{ C } \cos \left[\left(2 \pi \times 10^{6} \frac{ rad }{ m }\right) t -\left(\pi \times 10^{-2} \frac{ rad }{ s }\right) x \right]$ $E _{ z }=0 .$ The wave is :

The two ends of a rod of length $L$ and a uniform cross-sectional area $A$ are kept at two temperatures $T_1$ and $T_2 (T_1 > T_2).$ The rate of heat transfer, through the rod in a steady state is given by :

Heater coil $A$ takes $t_1 $ second to boil certain quantity of water. Heater coil $B$ takes $t_2 $ second to boil same quantity of water. If $A$ and $B$ are connected in series, the time taken to boil the same quantity of water by the combination is

To what temperature should the hydrogen at $ 327^{\circ}C $ be cooled at constant pressure, so that the root mean square velocity of its molecules becomes half of its previous value ?

The magnetic force acting on a charged particle of charge $-2 \mu C$ in a magnetic field of $2 T$ acting in y direction, when the particle velocity is is $ (2 \hat{i} + 3\hat{j}) \times 10^6 \, ms^{-1}$

In a satellite, if the time of revolution is $ T $ , then $ KE $ is proportional to

A particle performing $ SHM $ has time period $ \frac{2\pi}{\sqrt3} $ and path length $ 4\, cm $ . The displacement from mean position at which acceleration is equal to velocity is

A conducting circular loop is placed in a uniform magnetic field $0.04\, T$ with its plane perpendicular to the magnetic field. The radius of the loop starts shrinking at $2\, mm/s.$ The induced emf in the loop when the radius is $2\, cm$ is

In a resonance pipe the first and second resonances are obtained at depths $ 22.7 \,cm $ and $ 70.2\, cm $ respectively. What will be the end correction ?

If the linear charge density of a cylinder is $ 4 \,\mu cm^{-1} $ then electric field intensity at point $ 3.6 \,cm $ from axis is

Power dissipated in an $LCR$ series circuit connected to an a.c. source of emf $\varepsilon$ is :

In the nuclear decay given below $^A_Z X \rightarrow \, ^A _{Z+1} Y \rightarrow \, ^{A-A}_{Z-1}B * \, \rightarrow \, ^{A-A}_{Z-1}B,$ the particles emitted in the sequence are

Two identical light waves, propagating in the same direction, have a phase difference $\delta$. After they superpose the intensity of the resulting wave will be proportional to

Two rods of same area of cross section and lengths, and conductivities $K_1$ and $K_2$ are connected in series. Then, in steady state conductivity of the combination is

If the Earth shrinks in its size (radius) mass remaining the same, the value of g on its surface will

When a wave undergoes refraction

A cricket ball of mass $0.5\, kg$ strikes a cricket bat normally with a velocity of $20\, ms ^{-1}$ and rebounds with velocity of $10\, ms ^{-1}$. The impulse of the force exerted by the ball on the bat is