List of top Physics Questions

When the energy of the incident radiation is increased by $20 \%, $ the kinetic energy of the photoelectrons emitted from a metal surface increased from 0.5 eV to 0.8 eV. The work function of the metal is

In an ammeter 0.2% of main current passes through the galvanometer. If resistance of galvanometer is $G$, the resistance of ammeter will be

A solid cylinder of mass 50 kg and radius 0.5 m is free to rotate about the horizontal axis . A massless string is wound round the cylinder with one end attached to it and other hanging freely. Tension in the string required to produce an angular acceleration of 2 revolutions $ s^ {-2} $ is

A body of mass $(4m)$ is lying in $x-y$ plane at rest. It suddenly explodes into three pieces. Two pieces, each of mass $(m)$ move perpendicular to each other with equal speeds $(v)$. The total kinetic energy generated due to explosion is

If the temperature of the body is increased by $ 10\%, $ the percentage increase in the emitted indication will be

A uniform force of $(3\hat{i}+\hat{j}) $newton acts on a particle of mass 2 kg. Hence the particle is displaced from position $(2\hat{i}+\hat{k})$ metre to position $(4\hat{i}+3\hat{j}-\hat{k})$ metre. The work done by the force on the particle is

Choose the correct sketch of the magnetic field lines of a circular current loop shown by the dot ? and the cross ?.

The reddish appearance of the sun at sunrise and sunset is due to

Diameter of a plano-convex lens is $6 \,cm$ and thickness at the centre is 3 mm. If speed of light in material of lens is $2 \times 10^8$ m/s, the focal length of the lens is

The amplitude of a damped oscillator decreases to $0.9$ times its original magnitude is $5\, s$. In another $10\, s$ it will decrease to a times its original magnitude, where $\alpha$ equals

The image of an illuminated square is obtained on a screen with the help of a converging lens. The distance of the square from the lens is $40\, cm$. The area of the image is $9$ times that of the square. The focal length of the lens is :

Two blocks of masses $m$ and $M$ are connected by means of a metal wire of cross-sectional area $A$ passing over a frictionless fixed pulley as shown in the figure. The system is then released. If $M \,= \,2 m$, then the stress produced in the wire is:

A vessel contains a mixture of $1$ mole of oxygen and two moles of nitrogen at $300 \,K$. The ratio of the rotational kinetic energy per $ O_{2} $ molecule to that per $ N_{2} $ molecule is

A stone falls freely under gravity. It covers distances $h_1, \, h_2 $ and $h_3$ in the first 5 seconds, the next 5 seconds and the next 5 seconds respectively. The relation between $h_1 , \,h_2 $ and $h_3$ is

Two pith balls carrying equal charges are suspended from a common point by strings of equal length, the equilibrium separation between them is 7. Now the strings are rigidly clamped at half the height. The equilibrium separation between the balls now become

Infinite number of bodies, each of mass 2 kg are situated on x-axis at distance 1 m, 2 m, 4 m, 8 m respectively, from the origin. The resulting gravitational potential due to this system at the origin will be

An explosion breaks a rock into three parts in a horizontal plane. Two of them go off at right angles to each other. The first part of mass 1 kg moves with a speed of 12 $ms^{-1}$ and the second part of mass 2 kg moves with 8 $ms^{-1}$ speed. If the third part flies off with 4 $ms^{-1}$ speed, then its mass is

In an experiment four quantities a, b, c and d are measured with percentage error 1%, 2%, 3% and 4% respectively. Quantity P is calculated as follows: P= $\frac{a^3 b^2}{cd}$ % error in P is

The velocity of a projectile at the initial point A is (2i+3j) m/s. Its velocity (in m/s) at point B is

A wave travelling in the +ve x-direction having displacement along y-direction as 1 m, wavelength 2π in and frequency of $\frac1{π}$Hz is represented by

If we study the vibration of a pipe open at both ends, then the following statement is not true

The upper half of an inclined plane of inclination θ is perfectly smooth while lower half is rough. A block starting from rest at the top of the plane will again come to rest at the bottom, if the coefficient of friction between the block and lower half of the plane is given by

Three blocks with masses m, 2m and 3m are connected by strings, as shown in the figure. After an upward force F is applied on block m, the masses move upward at constant speed v. What is the net force on the block of mass 2 m? (g is the acceleration due to gravity)

A source of unknown frequency gives 4 beats/s, when sounded with a source of known frequency 250 Hz. The second harmonic of the source of unknown frequency gives five beats per second, when sounded with a source of frequency 513 Hz. The unknown frequency is

In Young's double slit experiment, the slits are 2 mm apart and are illuminated by photons of two wavelengths, $λ_1$ =12000 Å and $λ_2$= 10000 Å. At what minimum distance from the common central bright fringe on the screen 2 m from the slit will a bright fringe from one interference patter coincide with a bright fringe from the other?