Two identical spherical balls of mass \(M\) and radius \(R\) each are stuck on two ends of a rod of length \(2R\) and mass \(M\) (see figure). The moment of inertia of the system about the axis passing perpendicularly through the centre of the rod is

Two particles \({A}\) and \({B}\) having charges \(20\, \mu {C}\) and \(-5\, \mu {C}\) respectively are held fixed with a separation of \(5\, {cm}\). At what position a third charged particle should be placed so that it does not experience a net electric force?

Water from a tap emerges vertically downwards with an initial speed of \(1.0\,ms^{-1}.\) The cross-sectional area of the tap is \(10^{-4}\,m^2.\) Assume that the pressure is constant throughout the stream of water and that flow is streamlined. The cross-sectional area of the stream, \(0.15\,m\) below the tap would be: (take \(g = 10\,ms^{-2}\) )

Two metal plates \((A, B)\) are kept horizontally with separation of \(\left(\dfrac{12}{\pi}\right)\) cm, with plate A on the top. An atomizer jet sprays oil (density \(1.5\) g/cm\(^3\)) droplets of radius \(1\) mm horizontally. All oil droplets carry a charge \(5\) nC. The potentials \(V_A\) and \(V_B\) are required on plates A and B respectively in order to ensure the droplets do not descend. The values of \(V_A\) and \(V_B\) are _______.
(Neglect the air resistance to the droplets and take \(g = 10\) m/s\(^2\))

A transverse wave is represented by \(y=2 \sin\) \((\omega t - kx ) cm\). The value of wavelength (in \(cm\) ) for which the wave velocity becomes equal to the maximum particle velocity, will be.

A sample of gas at temperature \(T\) is adiabatically expanded to double its volume. The work done by the gas in the process is \(\left(\right.\) given, \(\left.\gamma=\frac{3}{2}\right)\) :

The electrostatic potential on the surface of uniformly charged spherical shell of radius \(\mathrm{R}=10 \mathrm{~cm}\) is 120 V. The potential at the centre of shell, at a distance \(\mathrm{r}=5 \mathrm{~cm}\) from centre, and at a distance \(\mathrm{r}=15 \mathrm{~cm}\) from the centre of the shell respectively, are :

A \(1\,m\) long wire is broken into two unequal parts \(X\) and \(Y\) The \(X\) part of the wire is streched into another wire \(W\). Length of \(W\) is twice the length of \(X\) and the resistance of \(W\) is twice that of \(Y\). Find the ratio of length of \(X\) and \(Y\).

The oscillating magnetic field in a plane electromagnetic wave is given by \(B _{ y }=5 \times 10^{-6} \sin\) \(1000\,\pi\left(5 x -4 \times 10^{8} t \right) T\). The amplitude of electric field will be.

The magnetic moments associated with two closely wound circular coils \(A\) and \(B\) of radius \(r_A=10 cm\) and \(r_B=20 cm\) respectively are equal if: (Where \(N _A, I _{ A }\) and \(N _B, I _{ B }\) are number of turn and current of \(A\) and \(B\) respectively)

Which level of the single ionized carbon has the same energy as the ground state energy of hydrogen atom ?