$2\mathrm{.}1$ Identify the electricity$-$generating technology$($ies$)$ which are most likely to benefit from pumped storage on a national network and justify your answer. $(5)2\mathrm{.}2$The complications of hydropower systems arise mostly from associated dams and reservoirs.$$ Examine this statement in terms of the common negative environmental impacts of hydropower. $(5)2\mathrm{.}3$ A single jet impulse turbine of $10$ MW capacity is to work under a head of $500$ m$.$ If the specific speed of the turbine is $10,$ the overall efficiency is $80\%.$ Determine the diameters of the jet and the bucket wheel. Assume the speed of the bucket wheel as $0\mathrm{.}46$ of the jet velocity. Use the specific number in the form $=()5/4,$ where N is the number of revolutions per minute. Assume gravity constant and density of water to be $9\mathrm{.}81$ m$/$s$2$ and $1000$ kg$/$m$3$ respectively.