A pipe open at both ends has a fundamental frequency \(f\) in air. The pipe is dipped vertically in water so that half of it is in water. The fundamental frequency of the air column is now ..... \(f\)

A circular ring and a solid sphere having same radius roll down on an inclined plane from rest without slipping. The ratio of their velocities when reached at the bottom of the plane is \(\sqrt{\frac{x}{5}}\) where \(\mathrm{x}=\) _____

An external pressure \(P\) is applied on a cube at \(0^o C\) so that it is equally compressed from all sides. \(K\) is the bulk modulus of the material of the cube and a is its coefficient of linear expansion. Suppose we want to bring the cube to its original size by heating. The temperature should be raised by

Two bodies are having kinetic energies in the ratio \(16: 9\). If they have same linear momentum, the ratio of their masses respectively is

A longitudinal wave is represented by \(x =10 \sin 2 \pi\left( nt -\frac{ x }{\lambda}\right) \,cm\). The maximum particle velocity will be four times the wave velocity if the determined value of wavelength is equal to .....................

An electron moving with speed \(v\) and a photon moving with speed \(c,\) have same D-Broglie wavelength. The ratio of kinetic energy of electron to that of photon is -

In a photoelectric effect experiment a light of frequency \(1.5\) times the threshold frequency is made to fall on the surface of photosensitive material. Now if the frequency is halved and intensity is doubled, the number of photo electrons emitted will be _______.

A parallel plate capacitor with plate separation \(5\) \(\mathrm{mm}\) is charged up by a battery. It is found that on introducing a dielectric sheet of thickness \(2 \mathrm{~mm}\), while keeping the battery connections intact, the capacitor draws \(25 \%\) more charge from the battery than before. The dielectric constant of the sheet is _______.

Water flows in a horizontal tube (see figure). The pressure of water changes by \(700\; \mathrm{Nm}^{-2}\) between \(\mathrm{A}\) and \(\mathrm{B}\) where the area of cross section are \(40\; \mathrm{cm}^{2}\) and \(20\; \mathrm{cm}^{2},\) respectively. Find the rate of flow of water through the tube. ........ \(\mathrm{cm}^{3} / \mathrm{s}\) (density of water \(=1000\; \mathrm{kgm}^{-3}\) )