Two mechanical waves travel on strings of equal length L and equal tension T. The linear mass densities are in ratio $\frac{\mu_{1}}{\mu_{2}}=\frac{1}{2}$. Find the ratio of time taken for a wave pulse to travel from one end to the other.

Six charges (four $+q$, two $-q$) are present at circle of radius $r$ and centred at origin as shown. Electric field at origin is .

Match the following : \begin{tabular}{|l|l|} \hline List -1 & List-II \\ \hline (A) Spring constant & (i) $ML^{2}T^{-2}K^{-1}$ \\ \hline (B) Thermal conductivity & (ii) $ML^{0}T^{-2}$ \\ \hline (C) Boltzmann constant & (iii) $ML^{2}T^{-2}A^{-2}$ \\ \hline (D) inductance & (iv) $ML^{2}T^{-3}K^{-1}$ \\ \hline & (v) $M^{1}L^{-1}T^{-2}$ \\ \hline & (vi) $ML^{2}T^{-2}$ \\ \hline \end{tabular}

A potential energy curve U vs x is shown. If $F_{AB}, F_{BC}, F_{CD}, F_{DE}$ are forces in respective regions, arrange magnitudes in decreasing order.

If the electric field of an EM wave is given by $60[\sin(3\times10^{14}t)+\sin(12\times10^{14}t)]$ at $x=0$ and it falls on a photosensitive material having work function $2.8 eV$, find the maximum kinetic energy (in eV) of the ejected electrons.