$3\mathrm{.}1$ Indicate whether the following statement is TRUE or FALSE by writing only 'True' or 'False' next to the question number $(3\mathrm{.}1)$ in the ANSWER BOOK.

The term, impulse, in impulse steam turbines describes the principle of operation.

$3\mathrm{.}2$ The nozzle velocity and angle in a two$-$stage velocity$-$compounded impulse turbine are $500\frac{m}{s}$ and $20.$ In the first stage of moving blades, relative angles are equal. In the second stage, the absolute inlet angle is $20,$ the relative angles are equal. The mean blade speed is $100\frac{m}{s}$ while the coefficient of velocity across the turbine is $90\%.$ The steam flow rate through the turbine can be assumed to be a unit kilogram.

From the given information, determine the following:

$3\mathrm{.}2\mathrm{.}1$ Use a scale of $30mm=100\frac{m}{s}$ to construct the turbine's velocity diagrams. On these diagrams, indicate all the lengths in millimetres and all the angles in degrees.

$3\mathrm{.}2\mathrm{.}2$ Use the diagrams constructed in QUESTION $3\mathrm{.}2$ to determine the diagram efficiency and the power developed.