Solution:

• The steam nozzle is a passage of varying cross-section by means of which the energy of steam is converted into kinetic energy.
• The nozzle is so shaped that it will perform this conversion of energy with minimum loss.
• One may also define a nozzle as an opening through which steam is passed from a region of high pressure to one of lower pressure so as to derive additional velocity.
• It is chiefly used for producing a large velocity steam jet. In other words, its chief use is to produce a jet of steam for the purpose of driving steam turbines.