An electron rotates in a circle around a nucleus having positive charge \(\mathrm{Ze}\). Correct relation between total energy ( \(E\) ) of electron to its potential energy \((U)\) is _______.

Match List\(-I\) with List\(-II.\)

List\(-I\)	List\(-II\)
\((a)\) Capacitance, \(C\)	\((i)\) \({M}^{1} {L}^{1} {T}^{-3} {A}^{-1}\)
\((b)\) Permittivity of free space, \(\varepsilon_{0}\)	\((ii)\) \({M}^{-1} {L}^{-3} {T}^{4} {A}^{2}\)
\((c)\) Permeability of free space, \(\mu_{0}\)	\((iii)\) \({M}^{-1} L^{-2} T^{4} A^{2}\)
\((d)\) Electric field, \(E\)	\((iv)\) \({M}^{1} {L}^{1} {T}^{-2} {A}^{-2}\)

Choose the correct answer from the options given below

Given below are two statements: Statement \(I\) : A time varying electric field is a source of changing magnetic field and vice-versa. Thus a disturbance in electric or magnetic field creates \(EM\) waves. Statement \(II\) : In a material medium. The \(EM\) wave travels with speed \(v =\frac{1}{\sqrt{\mu_{0} \varepsilon_{0}}}\). In the light of the above statements, choose the correct answer from the options given below

A particle is moving along the \(x-\)axis with its coordinate with the time '\(t\)' given be \(\mathrm{x}(\mathrm{t})=10+8 \mathrm{t}-3 \mathrm{t}^{2} .\) Another particle is moving the \(y-\)axis with its coordinate as a function of time given by \(\mathrm{y}(\mathrm{t})=5-8 \mathrm{t}^{3} .\) At \(\mathrm{t}=1\; \mathrm{s},\) the speed of the second particle as measured in the frame of the first particle is given as \(\sqrt{\mathrm{v}} .\) Then \(\mathrm{v}\) (in \(\mathrm{m} / \mathrm{s})\) is

A point object, \(O\) is placed in front of two thin symmetrical coaxial convex lenses \(L _1\) and \(L _2\) with focal length \(24\,cm\) and \(9\,cm\) respectively. The distance between two lenses is \(10\,cm\) and the object is placed \(6\,cm\) away from lens \(L _1\) as shown in the figure. The distance between the object and the image formed by the system of two lenses is .........\(cm\)

The combination of two identical cells, whether connected in series or parallel combination provides the same current through an external resistance of \(2 \,\Omega\). The value of internal resistance of each cell is ............ \(\Omega\)

Consider two uniform discs of the same thickness and different radii \(R _{1}= R\) and \(R _{2}=\alpha R\) made of the same material. If the ratio of their moments of inertia \(I_{1}\) and \(I_{2}\), respectively, about their axes is \(I _{1}: I _{2}=1: 16\) then the value of \(\alpha\) is

Your friend is having eye sight problem. She is not able lo see clearly a distant uniform window mesh and it appears to her as non-uniform and distorted. The doctor diagnosed the problem as