List of top Physics Questions

A metal surface is illuminated by light of two different wavelengths \(207\text{ nm}\) and \(414\text{ nm}\) . The maximum speeds of photoelectrons corresponding to these wavelengths are \(u_1\) and \(u_2\) respectively with \(u_1 : u_2 = 2 : 1\). The work function of the metal is (\(hc = 1242\text{ eV nm}\))

A stone is thrown upward with a speed 'u' from the top of a tower reaches the ground with velocity ' \(3u\) '. The height of the tower is ( \(g\) = acceleration due to gravity)

For a common emitter transistor configuration the ratio of \(\frac{I_C}{I_E} = 0.96\), then the current gain in this configuration is

A spherical body of radius ' \(r\) ' radiates power ' \(P\) ' at \(T\) kelvin. If the radius is halved and the temperature doubled the power radiated in the same time ' \(t\) ' will be

A pendulum is performing simple harmonic motion. The acceleration of the bob is \(20\text{ cm s}^{-2}\) at a distance of \(5\text{ cm}\) from mean position. The time period of oscillation is

Which one of the following is the correct equation for the electric circuit shown?

Two uniform strings ' A ' and ' B ' made of steel are made to vibrate under same tension. If the first overtone of ' A ' is equal to second overtone of ' B ' and radius of ' A ' is twice that of ' B '. Then the ratio of length of string ' A ' to that of ' B ' is

Diode and resistance are connected as shown. Which statement is TRUE?

Work done to get ' \(n\) ' spherical drops of equal size from a single spherical drop of water, is proportional to

In biprism experiment the maximum intensity is ' \(I_0\) '. If the path difference between the two interfering waves is ' \(\lambda/4\) ' then intensity at the point on the screen is \(\left[ \sin 45^\circ = \cos 45^\circ = \frac{1}{\sqrt{2}} \right]\)

Four point masses, each of mass $m$ are arranged in $X-Y$ plane as shown. Find the moment of inertia about $X$-axis.

The angular momentum of electron in hydrogen atom in first orbit is ' \(L\) '. The change in angular momentum if electron is in second orbit of hydrogen atom is

A satellite is revolving round the earth with orbital speed ' \(V_0\) '. If it stops suddenly, the speed with which it will strike the surface of the earth would be ( \(V_e\) = escape velocity of a particle on earth's surface)

A particle of mass ' \(m\) ' is executing S.H.M. about the origin on \(x\)-axis with frequency \(\sqrt{\frac{ka}{\pi m}}\), where ' \(k\) ' is a constant and ' \(a\) ' is the amplitude of S.H.M. If ' \(x\) ' is a displacement of a particle, at time ' \(t\) ', potential energy of the particle will be

For a given medium, the speed of light and the polarising angle are ' \(v\) ' and ' \(i_p\) ' respectively, then (\(c\) = speed of light in vacuum)

A hollow charged metal sphere has a radius ' \(r\) '. If the potential difference between its surface and a point at a distance ' \(3r\) ' from the centre is ' \(v\) ', then the electric field intensity at a distance ' \(3r\) ' is

Two stars 'A' and 'B' radiate maximum energy at \(5200\text{ \AA}\) and \(6500\text{ \AA}\) respectively. Then the ratio of absolute temperatures of stars ' A ' and ' B ' is

A pipe closed at one end vibrating in fifth overtone is in unison with open pipe vibrating in its fifth overtone. The ratio of \(l_c : l_o\) is [\(l_c = \text{vibrating length of closed pipe}, l_o = \text{vibrating length of open pipe}\)]

When a ray of light is refracted from one medium to another, then the wavelength changes from \(6000\text{ \AA}\) to \(4000\text{ \AA}\). The critical angle for the interface will be

The resistance of a coil for d.c. is \(5\Omega\). In a.c., the resistance will

A thin rod of length ' $4L$ ' and mass ' $4m$ ' is bent as shown. Find the moment of inertia about an axis through $O$ and perpendicular to the plane.

In between the plates of parallel plate capacitor of plate separation '$d$' a dielectric plate of thickness '$t$' is inserted. The capacitance becomes one-third of the original capacity without dielectric. The dielectric constant of the plate is

Four masses of \(1\text{ kg}, 2\text{ kg}, 3\text{ kg}\) and \(4\text{ kg}\) are kept at co-ordinates \((0, 0)\text{m, (0, 1)\text{m}\) and \((1, 0)\text{m}\) respectively. Using the co-ordinates of centre of mass its position vector is}

Two different coils have self - inductance \(L_1 = 9\text{ mH}\) and \(L_2 = 3\text{ mH}\). The current in first coil is increased at a constant rate. The current in the second coil is also increased at the same constant rate. At certain instant of time, the power given to the two coils is same. At that time, there was current and induced voltage in the two coils. At the same instant, the ratio of the energy stored in the first coil to that in second coil is

Water is flowing through a horizontal pipe in a streamline flow. At the narrowest part of the pipe