List of top Physics Questions

What is the value of linear velocity, if angular velocity is $3 \hat i - 4 \hat j + \hat k$ and distance from the centre is $5 \hat i - 6 \hat j + 6 \hat k$ ?

The angular momentum of a system of particles is not conserved :

Figure shows a body of mass m moving with a uniform speed $v$ along a circle of radius $r$. The change in velocity in going from $A$ to $B$ is:

A square wire frame of size $L$ is dipped in a liquid. On taking out, a membrane is formed. If the surface tension of liquid is $T$, the force acting on the frame will be :

Angular width $ (\theta ) $ of central maximum of a diffraction pattern of a single slit does not depend upon:

The first overtone of a stretched wire of given length is $320 \,Hz$. The first harmonic is :

Two identical conducting rods are first connected independently to two vessels, one containing water at 100$^{\circ}$C and the other containing ice at 0$^{\circ}$C. In the second case, the rods are joined end to end and connected to the same vessels. Let q$_1$ and q$_2$ gram per second be the rate of melting of ice in the two cases respectively. The ratio $\frac{q_1}{q_2}$ is

A black body at $200\, K$ is found to exit maximum energy at a wavelength $14\, \mu\, m$ When its temperature is raised to $1000\, K$, then wavelength at which maximum energy emitted is

The electric potential at the surface of an atomic nucleus $(Z=50)$ of radius $9.0 \times 10^{-13} cm$ is

One milligram of matter converted into energy, will give

The capacity of a condenser is $4 \times 10^{-6} F$ and its potential is $100\, V$. The energy released on discharging it fully will be

The half-life of radium is $1620\, yr$ and its atomic weight is $226\, kg$ per kilomol. The number of atoms that will decay from its $1\, g$ sample per second will be (Avogadro's number $N=6.023 \times 10^{23}$ atoms/ $mol$ )

$20 \,A$ current is flowing in a long straight wire. The intensity of magnetic field at a distance of $10\, cm$ from the wire, will be

An electron having charge $1.6 \times 10^{-19} C$ and mass $9 \times 10^{-31} kg$ is moving with $4 \times 10^{6} m / s$ speed in a magnetic field of $2 \times 10^{-1} T$ in a circular orbit. The force acting on an electron and the radius of circular orbit will be

If $E_{1}$ be the electric field strength of a short dipole at a point on its axial line and $E_{2}$ that on the equatorial line at the same distance, then

Deuteron and alpha particle in air are at separation $1\,?$ The magnitude of electric field intensity on $\alpha$-particle due to deuteron is

In a simple microscope, if the final image is located at $25\, cm$ from the eye placed close to the lens, then the magnifying power is

An ideal gas expands isothermally from a volume $V_1$ to $ V_2$and then compressed to original volume $V_1$ adiabatically. Initial pressure is p$_1$ and final pressure is p$_3$. The total work done is W. Then,

After 280 days, the activity of a radioactive sample is 6000 dps. The activity reduces to 3000 dps after another 140 days. The initial activity of the sample in dps is

A source of sound of frequency 600 Hz is placed inside water. The speed of sound in water is 1500m/s and in air it is 300 m/s. The frequency of sound recorded by an observer who is standing in air is

A particle is placed at the origin and a force F = kx is acting on it (where k is a positive constant). If U (0) = 0, the graph of U (x) versus x will be (where U is the potential energy function)

Liquid oxygen at 50 K is heated to 300 K at constant pressure of 1 atm. The rate of heating is constant. Which of the following graphs represent the variation of temperature with time?

The ratio of electrostatic and gravitational forces acting between electron and proton separated by a distance $5 \times 10^{11} m$, will be (Charge on electron $=1.6 \times 10^{-19} C$, mass of electron $=9.1 \times 10^{-31} kg$, mass of proton $=1.6 \times 10^{-27} kg$ $\left.G=6.7 \times 10^{-11} Nm ^{2} / kg ^{2}\right)$

A stone is thrown with an initial speed of $4.9\, m / s$ from a bridge in vertically upward direction. It falls down in water after $2\, \sec$. The height of bridge is

The half-life of a radioactive substance is $3.6$. How much of $20\,mg$ of this radioactive substance will remain after $36$ days ?