A force of \(40\, N\) acts on a point \(B\) at the end of an \(L-\) shaped object, as shown in the figure. The angle \(\theta\) that will produce maximum moment of the force about point \(A\) is given by

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 \(g = 10\,ms^{-2}\) )

The energy equivalent of \(1 \mathrm{~g}\) of substance is _______.

In a double slit experiment, when one of the slits is covered by a transparent mica sheet of refractive index \(1.56\), the central fringe shifts to the position of \(7^{th}\) bright fringe, obtained with both slits uncovered. If the light source wavelength is \(450\) nm, the thickness of mica sheet is \(\alpha \times 10^{-9}\) m. The value of \(\alpha\) is ______.

The velocity of sound in a gas. in which two wavelengths \(4.08\,m\) and \(4.16\,m\) produce \(40\) beats in \(12\,s\), will be ..............\(ms ^{-1}\)

de-Broglie wavelength of an electron accelerated by a voltage of \(50\,\,V\) is close to ............. \(\mathop {\rm{A}}\limits^o \)  \((\left| e \right| = 1.6 \times {10^{ - 19}}\,\,C,\,\,{m_e} = 9.1 \times {10^{ - 31}}\,kg,\,\,h = 6.6 \times {10^{ - 34}}\,\,Js)\)

A radioactive sample disintegrates via two independent decay processes having half lives \(T _{1 / 2}^{(1)}\) and \(T _{1 / 2}^{(2)}\) respectively. The effective half- life \(T _{1 / 2}\) of the nuclei is

From the given data, the amount of energy required to break the nucleus of aluminium \({ }_{13}^{27} {Al}\) is \(....\,x \times 10^{-3} {J}\) Mass of neutron \(=1.00866 \,{u}\) Mass of proton \(=1.00726 \,{u}\) Mass of aluminium nucleus \(=27.18846\, {u}\) (Assume \(1\,u\) corresponds to \(x\,J\) of energy) (Round off to the nearest integer)

Two large plane parallel conducting plates are kept 10 cm apart as shown in figure. The potential difference between them is \(V\). The potential difference between the points A and B (shown in the figure) is :

Assuming the validity of Bohr's atomic model for hydrogen like ions the radius of \(\mathrm{Li}^{++}\)ion in its ground state is given by \(\frac{1}{X} a_0\), where \(X=\) _______. (Where \(\mathrm{a}_0\) is the first Bohr's radius.)