List of top Physics Questions

A concave mirror of focal length $f$ produces a real image $n$ times the size of the object. The distance of the object from the mirror is
A compound microscope has a magnification of $ 30 $ . The focal length of the eye-piece is $ 5\,cm $ If the final image is formed at the least distance of distinct vision $ (25\,\,cm) $ the magnification produced by the objective is
A beam of parallel light rays is incident on a solid transparent sphere of refractive index $ \mu $ . If a point image is produced just at the back of the sphere, what is the refractive index of the sphere?
Four conductors carrying $2.0\, A$ of current into or out of the page are shown in the diagram. $A$ path $C$ is indicated for the line integral $\oint B$. $d s$. Find the value of the integral for the path $C$.
In a container, $200 \,g$ of aluminum (specific heat $900\, J / kg K$ ) at $100^{\circ} C$ is mixed with $50\, g$ of water at $20^{\circ} C$, with the mixture thermally isolated. Find the entropy change of the aluminumwater system.
A $70 \,cm$ long sonometer wire is in unison with a tuning fork. If the length of the wire is decreased by $1.0\, cm$, it produces $4$ beats per second with the same tuning fork. The frequency of the tuning fork is
A straight wire of mass $300 \,g$ and length $ 2.5\,m $ carries a current of $ 3.5\,A $ . It is suspended in mid-air by a uniform horizontal magnetic field $B$. What is the magnitude of the magnetic field?
A solenoid of length $0.6 \,m$ has a radius of $1 \,cm$ and is made up of $600$ turns. It carries a current of $6 \,A$. What is the magnitude of the magnetic field inside the solenoid?
The bus moving with a speed of $42 \,km / h$ is brought to a stop by brakes after $6\, m$. If the same bus is moving at a speed of $90 \,km / h$, then the minimum stopping distance is
The Lenz's law is the consequence of the conservation of
The waves used for line-of-sight $(LOS)$ communication is
The ratio of the energy required to raise a satellite upto a height $h$ above the earth of radius $R$ to that the kinetic energy of the satellite into that orbit is
The power of biconvex lens is 10 dioptre and the radius of curvature of each surface is 10 cm. Then the refractive index of the material of the lens is
The dimensional formula for electric flux is
Sodium in sodium vapour lamp produces
In an isothermal process, there is
If a planet has twice the mass of earth and three times the radius $(R)$ of earth, then the escape velocity of the planet is ($\upsilon_e$ = escape velocity of earth)
A stone tied at the end of a string 80 cm long is whirled in a horizontal circle with a constant speed. If the stone makes 25 revolutions in 14 s, what is the magnitude of acceleration of the stone ?
A tank full of water has a small hole at its bottom. If one-fourth of the tank is emptied in $t_1$ seconds and the remaining three fourths of the tank is emptied is $t_2$ seconds, then ratio $(t_1/t_2)$ is
A real gas behaves as an ideal gas,
A piece of brass (alloy of copper and zinc) weighs 12.9 g in air. When completely immersed in water it weighs 11.3 g. What is the mass of copper contained in the alloy ? (Specific gravities of copper and zinc are 8.9 and 7.1 respectively)
A particle is moving on a circular path of 10 m radius. At any instant of time, its speed is ${5\, m \, s^{-1}}$ and the speed is increasing at a rate of ${2\, m \, s^{-2}}$. The magnitude of net acceleration at this instant is
A galvanometer can be converted into a voltmeter by connecting a
A closed organ pipe and an open organ pipe of same length produce $2 \,beats/second$ when they are set into vibrations together in fundamental mode. The length of open pipe is now halved and that of closed pipe is doubled. The number of beats produced will be
A circular coil of $n$ turns and radius $R$ has a magnetic induction of strength at its centre is