Classification of Hydroplants - MCQs with answers
Q1. The location of surge tank is close to ____________.a. Tailrace
b. Dam
c. Turbine gate
d. Spillway
View Answer / Hide AnswerANSWER: c. Turbine gate
Explanation: The load on the generator keeps on fluctuating, when the governor opens the turbine gates suddenly to intake more water there is a tendency to create a vacuum in penstock. Its main function is to absorb these sudden changes in water requirements so as to prevent water hammer and vacuum. So it is desired to be placed near the power house i.e. turbine gates.
a. 200 m – 500 m
b. 30 m – 200 m
c. Less than 30 m
d. More than 500 m
View Answer / Hide AnswerQ3. The specific speed of a water turbine is_________.a. Maximum speed i.e ((120*f) / P)
b. Minimum metric H.P
c. Unit H.P at all heads
d. Unit H.P under a unit head
View Answer / Hide AnswerANSWER: d. Unit H.P under a unit head
Explanation: specific speed of a turbine is the speed of a scale model of turbine which develops a metric H.P under a head of one metre. The specific speed is given by, Ns = (N √Pt ) / H1.25 , where N is the speed of turbine in rpm, Pt is the power output in metric H.P, and H is the effective head in m.
a. 30 m
b. 50 m
c. 100 m
d. 75 m
View Answer / Hide AnswerANSWER: a. 30 m
Explanation: Propeller turbines are reaction turbine which is suitable for low head and large quantity of water. It is mainly suitable for heads below 30m.
a. High speed turbines
b. High head and axial flow turbines
c. Low head and axial flow turbines
d. High pressure turbine
View Answer / Hide AnswerANSWER: c. Low head and axial flow turbines
Explanation: The bulb turbine is an axial flow turbine; it is so called because water flows through the machine coaxial with the turbine shaft. It is specially designed for the low heads. These turbines are mainly suitable for the tidal plants. These turbines also have many advantages like it can be used for both very low and widely varying heads with a high efficiency due to the axial flow. They are easy and cheaper in construction.
a. Spillway
b. Penstock
c. Turbine casing
d. Surge tank
View Answer / Hide AnswerANSWER: b. Penstock
Explanation: sudden closure of turbine gates creates an increased pressure, which is called the water hammer occurring in the penstock. The water intake is limited with the help of water governor, which closes the turbine gate when the load is reduced. The surge tank helps in stabilising the velocity and the pressure in the penstock and reduces the water hammer and vacuum. The high pressure turbines are made from thick steel pipes.
a. Does not exist
b. Bhakra Nangal (Punjab, Himachal Pradesh)
c. Kadamparai (Tamilnadu)
d. Koyna (Maharashtra)
View Answer / Hide AnswerANSWER: c. Kadamparai (Tamilnadu)
Explanation: This type of plants have been introduced recently. There are only five plants with this scheme. The dams with this facility are :
1. Nagarjunasagar (AP) on Krishna river
2. Paithon (Maharashtra) on Godavari river
3. Kadamparai (Tamilnadu) on kadamparai river
4. Panchet hill on Damodar river
5. Kadana (Gujarat) on mahi river
a. Operating cost is high and initial cost is high
b. Operating cost is low and initial cost is high
c. Operating cost is low and initial cost is low
d. Operating cost is high and initial cost is low
View Answer / Hide AnswerANSWER: b. Operating cost is low and initial cost is high
Explanation: The fuel cost involved in the hydro plants is zero as water is free of cost. The cost involved in the construction and the setup is high, which is only one time investment. A large amount of forest land and villages are submerged in the catchment area. The cost involved in the production of electricity is very low as there are no fuel charges.
