Steam and Gas Turbines Multiple Choice Questions on “Energy Distribution and Effect of Carry Over Velocity”.
1. Most of the energy produced by gas turbine is utilized by _______
a) compressor
b) condenser
c) to drive turbine blade
d) none of the mentioned
Answer: a
Clarification: Two third of the energy produced by gas turbine is utilized by the compressor to compress the air.
2. In gas turbines during expansion rotor’s blades rotate, which is an __________ transformation.
a) reversible
b) irreversible
c) no energy transformation occurs by rotation of rotor blades
d) none of the mentioned
Answer: b
Clarification: Rotation of rotor blades is an irreversible transformation.
3. Energy losses in gas turbines are __________
a) flue gasses energy loss
b) rotational loss
c) flue gasses energy & rotational loss
d) none of the mentioned
Answer: c
Clarification: Flue gases loss and rotational loss are some of the energy losses in gas turbine.
4. In steam turbines carry over losses are due to _____________
a) formation of eddies in annular spaces
b) decrease in pressure
c) increase in temperature
d) none of the mentioned
Answer: a
Clarification: Carry over losses are due to formation of eddies in steam turbines.
5. Corrosion and Erosion takes place if dryness factor of steam is __________ in last stage.
a) less than 0.68
b) more than 0.60
c) less than 0.88
d) none of the mentioned
Answer: c
Clarification: Liquid particles have lesser velocity than steam particles and hence if dryness fraction is less than 0.88 even erosion and corrosion can takes place.
6. Radiation losses can be covered by _______
a) decreasing the temperature of steam
b) proper insulation
c) decreasing the temperature of steam and proper insulation
d) none of the mentioned
Answer: b
Clarification: Radiation and convention losses can be reduced by proper insulation.
7. Enthalpy __________ takes place when steam enters from turbine to condenser.
a) decrease
b) increase
c) depends on the situation
d) none of the mentioned
Answer: a
Clarification: When steam leaving turbine has kinetic energy and when it enters condenser enthalpy loss takes place.
8. Energy balance states that total energy input is equal to arithmetic sum of Energy losses, output work, flue gasses loss and rotational loss.
a) True
b) False
Answer: a
Clarification: Energy balance equation states that
Total energy input = Energy output + energy losses + flue gasses loss + rotational loss.
9. ______________ is commonly called as carry over velocity.
a) Compressor velocity
b) Inlet velocity
c) Exit velocity
d) None of the mentioned
Answer: c
Clarification: Velocity at exit is called carryover velocity.
10. Carryover loss is also called a leaving loss.
a) True
b) False
Answer: a
Clarification: Loss in exit velocity is called carryover loss or leaving loss.