1. What is the use of surge tank?
a) To store condensate
b) To prevent surging
c) To provide better regulation of water pressure in the system
d) To prevent chocking
Explanation: The surge tank controls the water when the load on the turbine decreases and supplies water when the load on the turbine increases.
2. What is the function of Fore bay?
a) Temporary water storage
b) Steam passage
c) Water flow in penstock
d) Condensate storage
Explanation: It is temporary water storage when the load on the plant is reduced and provides water for initial increment on increasing load.
3. What is the use of draft tube?
a) To regain kinetic energy
b) To regain potential energy
c) Passage for water
d) Stores energy
Explanation: The draft tube is used to regain the kinetic energy of water coming out of reaction turbine. It enables the reaction turbine to be placed over tailrace level.
4. Is regenerative cycle alone useful?
a) yes
b) no
c) may be
d) depends on other factors
Explanation: Feedwater is preheated so as to decrease fuel consumption which increases efficiency.
5. What is the function of surge tank?
a) Regulation of water pressure
b) Regulation of steam pressure
c) Storage
d) Regulation of lubricants
Explanation: The surge tank controls the water when the load on the turbine decreases and supplies water when the load on the turbine increases
6. External Thermal Irreversibility can be removed by which of the following process?
a) Reheat
b) Regeneration
c) Pre-heat
d) None of the mentioned
Explanation: In the process of regeneration, energy is exchanged internally between the expanding fluid in the turbine & the compressed fluid before heat addition.
7. When is the relation between mean temperature of heat addition (T) with regeneration & without regeneration?
a) (Tml)with regeneration is independent of (Tml)without regeneration
b) (Tml)with regeneration > (Tml)without regeneration
c) (Tml)with regeneration < (Tml)without regeneration
d) (Tml)with regeneration = (Tml)without regeneration
Explanation: The efficiency of the regenerative cycle will be higher than that of the Rankine cycle. Hence, the relation between mean temperature of heat addition (Tml) with regeneration & without regeneration is,
(Tml)with regeneration > (Tml)without regeneration.
8. What is the relation between energy gain of feedwater & energy given off by vapour in condensation?
a) energy gain of feedwater > energy given off by vapour in condensation
b) energy gain of feedwater < energy given off by vapour in condensation
c) energy gain of feedwater = energy given off by vapour in condensation
d) none of the mentioned
Explanation: Here heaters are assumed to be adequately insulated, & there is no heat gain from or heat loss to, the surrounding.
9. The product of Steam rate & the difference of work done between turbine & pump, when the steam rate is expressed in kg/kWh is equal to?
a) 36
b) 60
c) 360
d) 3600
Explanation: The steam rate in terms of kg/kWh is given by the expression as,
Steam Rate = 3600/(Wt – WP) kg/kWh
10. The product of cycle efficiency & heat input is given by which of the following relations?
a) Wt – WP
b) Wt x WP
c) Wt / WP
d) none of the mentioned
Explanation: The expression for cycle efficiency n is given by the following expression,
n = (Wt – WP)/(Q1)