List of top Physics Questions

If the wavelength of 1st line of Balmer series of hydrogen is 6561 ?, the wavelength of the 2 line of series will be

An atom bomb is based on the principle of

Which of the following circular rods, (given radius $r$ and length $l$) each made of the same material and whose ends are maintained at the same temperature will conduct most heat?

A stone of mass 0.3 kg attached to a 1.5 m long string is whirled around in a horizontal circle at a speed of 6 ms. The tension in the string is

A sound absorber attenuates the sound level by 20 dB. The intensity decreases by a factor of

A projectile is thrown in the upward direction making an angle of 60$^{\circ}$ with the horizontal direction with a velocity of 147 $ms^{ - 1}$ Then the time after which its inclination with the horizontal is 45$^{\circ}$, is

A ray is incident on a plane surface. If $\hat{i} + \hat{j} - \hat{k}$ represents a vector along the direction of incident ray.$\hat{i} + \hat{j} $ is a vector along normal on incident point in the plane of incident and reflected ray, then vector along the direction of reflected ray is

A circuit is made up of a resistance $1\, \Omega$ and inductance $0.01\, H$. An alternating emf of $200\, V$ at $50\,Hz$ is connected, then the phase difference between the current and the emf in the circuit is

A motor cycle is going on an overbridge of radius $R$. The driver maintains a constant speed. As the motor cycle is ascending on the overbridge, the normal force on it

A coil of inductance 300 mH and resistance 2 $\Omega$ is connected to a source of voltage 2 V. The current reaches half of its steady state value in

Hard X-rays for the study of fractures in bones should have a minimum wavelength of $10^{-11}$ m. The accelerating voltage for electrons in X-ray machine should be

Interference was observed in a chamber when air was present. Now, the chamber is evacuated and if the same light is used, a careful observation will show

A leaf which contains only green pigments, is illuminated by a laser light of wavelength 0.6328 mm. It would appear to be

The north pole of a long horizontal bar magnet is being brought closer to a vertical conducting plane along the perpendicular direction. The direction of the induced current in the conducting plane will be

The respective speeds of five molecules are 2, 1.5, 1.6, 1.6 and $1.2 \, km \, s^{-1}$, the most probable speed in ${km\, s^{-1}}$ will be

The displacement of a particle is given by $x = a_0 + \frac{a_1 t}{2} - \frac{a_2 t^2}{3}$, what is its acceletion ?

Two thin lenses have a combined power of $+9 D$. When they are separated by a distance of $20\, cm$, their equivalent power becomes $ +\frac{27}{5} D$. Their individual powers (in diopters) are

The displacement-time graphs of two moving particles make angles of $30^{\circ}$ and $45^{\circ}$ with the time $X$ -axis The ratio of their velocities is

If the scattering intensity of a liquid is $8$ units at a wavelength of $500\, nm$, then the scattering intensity at a wavelength of $400\, nm$ will be approximately

A solid sphere of mass $m$ rolls down an inclined plane without slipping, starting from rest at the top of an inclined plane. The linear speed of the sphere at the bottom of the inclined plane is $v$. The kinetic energy of the sphere at the bottom is

Flash spectrum confirms a/an

A person of mass $60\,kg$ is inside a lift of mass $940\,kg$ and presses the button on control panel. The lift starts moving upwards with an acceleration $1.0 \,m/s^2$. If $g = 10\, ms^{-2}$, the tension in the supporting cable is

Force $F$ on a particle moving in a straight line varies with distance $d$ as shown in figure. The work done on the particle during its displacement of $12\, m$ is

Charge $q$ is uniformly spread on a thin ring of radius $R$. The ring rotates about its axis with a uniform frequency $f\,Hz$ . The magnitude of magnetic induction at the center of the ring is