MCQs on Power Systems

Page 59 of 67. Go to page
01․ In Francis turbine runner, the number blades is usually of the order of
3 - 6.
6 - 8.
12 - 14.
16 - 24.

The runner blade of Francis turbine is order 16 to 24.
02․ For variable heads of near about but less than 30 m, which type of turbines is used hydro power plant
Pelton.
Francis.
Kaplan.
None of above.

Because of highest specific speed, the Kaplan turbine is suitable for low head and it is less than always 30 m.
03․ The specific speeds of Kaplan, Francis and Pelton turbines are in
the decreasing order.
the increasing order.
neither increasing nor decreasing order.
none of the above.

The specific speed of Kaplan, Francis and Pelton turbines are in order of 300 to 1000, 60 to 300 and 10 to 50 in metric units respectively.
04․ The specific speed of water turbine is the speed at which the turbine develops
maximum horse power.
a minimum horse power.
unit horse power at unit head.
unit horse power at all heads.

The specific speed of the turbines is defined as the speed of a geometrically similar turbine that would develop one metric horse power under a head of one metre.
05․ On what factors does the selection of a water turbine depend
Working head.
Speed.
Nature of load.
All of above.

The effective head under which the turbine is to operate gives the first guide to the selection of the type of turbine. Even for the same working head two different type turbine may be employed. For an e.g, for a head of 200 m either of Pelton or Francis turbine can be used. Similarly for a head of 30 m, either of the Kaplan or Francis turbine can be employed. A runner of high specific speed will generate more power for the same head resulting in small size of the and power house. The selection of water turbine is depends upon the nature of load.
06․ Francis, Kaplan and propeller turbines fall under the category of
Reaction turbine.
Impulse turbine.
Impulse-reaction combined.
Axial flow.

The reaction turbine have a runner that always functions within a completely water filled casing. So the Kaplan, Francis and propeller are the reaction turbine.
07․ Deflectors are provided in
Kaplan turbine.
propeller turbine.
Pelton wheel.
Francis turbine.

Deflector are provided is Pelton wheels to control the speed.
08․ The function of draft tube is reaction turbine is to
increase flow rate of water.
convert kinetic energy of water.
reduce water hammer.
all of above.

Draft tube is provided to increase the acting head on the water wheel. Thus it converts the wasteful kinetic energy at the exit of the runner into the useful pressure energy.
09․ One atomic mass unit is equivalent to
120.4 MeV.
180.5 MeV.
251.2 MeV.
931.4 MeV.

According to Einstein mass and energy are interchangeable and the relation between them is given by
W = mc2
Where W = energy in joules, m = mass in Kg and C = Speed of light = 3 × 108 m/sec. \
10․ Which one of following fuels is used by slow thermal nuclear reaction for power generation
U238.
U235.
Th232.
Pu239.

Materials fissionable by thermal or low-speed neutrons are U235, Pu239, U233 etc.
<<<5758596061>>>