List of top Physics Questions

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 ?

A siren emitting sound of frequency $500\, Hz$ is going away from a stationary listener with a speed of $50\, m / s$, the frequency of sound heard directly from the siren is

The work done in pulling up a block of wood weighing $2\, kN$ for a length of $10\, m$ on a smooth plane inclined at an angle of $15^{\circ}$ with the horizontal is

A circular coil of mean radius of $7\, cm$ and having $4000$ turns is rotated at the rate of $1800$ revolutions per minute in the earth's magnetic field $(B=0.5$ gauss), the emf induced in coil will be

If the heat of $110\, J$ is added to a gaseous system, whose internal energy is $40\, J$, then the amount of external work done is

Consider a system of two particles having masses $m_1$ and $m_2$. If the particle of mass $m_1$ is pushed towards the mass centre of particles through a distance '$d$', by what distance would be particle of mass $m_2$ move so as to keep the mass centre of particles at the original position ?

A mass of $0.5 \,kg$ moving with a speed of $1.5 \,m/s$ on a horizontal smooth surface, collides with a nearly weightless spring of force constant $k = 50 \,N/m$. The maximum compression of the spring would be

A ray of light is incident on an equilateral glass prism placed on a horizontal table. For minimum deviation which of the following is true ?

If $ \lambda_m $ denotes the wavelength at which the radiative emission from a black body at a temperature $T\, K$ is maximum, then

A resonance air column of length $40\,cm$ resonates with a tuning fork of frequency $450 \,Hz$. Ignoring end correction, the velocity of sound in air will be :

The energy in $MeV$ is released due to transformation of $1\, kg$ mass completely into energy, is $\left(c=3 \times 10^{8} m / s \right)$

A charged particle is suspended in equilibrium in a uniform vertical electric field of intensity $20000\, V / m$. If mass of the particle is $9.6 \times 10^{-16} kg$, the charge on it and excess number of electrons on the-particle respectively are $\left( g =10\, m / s ^{2}\right)$

$20\, kV$ potential is applied across $X$-ray tube, the minimum wavelength of $X$-ray emitted will be

The mass of proton is 1.0073 u and that of neutron is 1.0087 u (u = atomic mass unit). The binding energy of  \(_2^4 He\) is (Given: helium nucleus mass ≈ 4.0015 u) 

In which of the following systems will be radius of the first orbit (n=1) be minimum: