1.In outward radial flow reaction turbines, tangential velocity at inlet is less than that of the outlet.
a) False
b) True
Explanation: In outward radial flow reaction turbines, tangential velocity at inlet is less than that of the outlet as the inlet of the runner is the inner diameter.
2. In an outward radial flow reaction turbine the ratio of tangential wheel at inlet to given velocity of jet is known as ___________
a) Speed ratio
b) Flow ratio
c) Discharge
d) Radial discharge
Explanation: Flow ratio is known as ratio of tangential wheel at inlet to given velocity of jet and it is scalar quantity.
3. In an outward radial flow reaction turbine the ratio of tangential velocity at inlet to the given velocity is ______
a) Speed ratio
b) Flow ratio
c) Discharge
d) Radial discharge
Explanation: Speed ratio is ratio of tangential velocity at inlet to the given velocity and it is scalar quantity because it is ratio of two speeds.
4. Discharge in an outward flow reaction turbine ____________
a) Increases
b) Decreases
c) Remains constant
d) Gradually decreases
Explanation: Discharge in an outward flow reaction turbine increases because area increases as fluid flows across spiral structure in the turbine.
5. An outward radial reaction turbine has ______
a) u1 < u2
b) u1 > u2
c) u1 = u2
d) u2 = u1 = 0
Explanation: For an outward flow reaction turbine, tangential velocity at inlet should be less than the tangential velocity at outlet.
6. An outward flow reaction turbine, ________
a) D1 > D2
b) D1 < D2
c) D1 = D2
d) D1 = D2 = 0
Explanation: In an outward flow reaction turbine, to maintain flow of water, the inlet diameter should be less than outlet diameter.
7. ___________is ratio of pressure energy change inside runner to total energy change inside runner
a) Degree of reaction
b) Speed ratio
c) Flow ratio
d) Hydraulic efficiency
Explanation: This is just a formula and it is scalar quantity because it is ratio of two changes of energies.
8. Degree of reaction for impulse turbine
a) 0
b) 1
c) 2
d) 3
Explanation: For pelton turbine u1=u2 and Vr1=Vr2 by substituting these values in degree of reaction we get it as 0.
9. The formula for degree of reaction for hydraulic turbines is __________
a) 1- (V1*V1-V2*V2)/(V1*V1-V2*V2)*(u1*u1-u2*u2)*(Vr2*Vr2-Vr1*Vr1)
b) (V1*V1-V2*V2)/ (V1*V1-V2*V2)*(u1*u1-u2*u2)*(Vr2*Vr2-Vr1*Vr1)
c) 1+ (V1*V1-V2*V2)/ (V1*V1-V2*V2)*(u1*u1-u2*u2)*(Vr2*Vr2-Vr1*Vr1)
d) 1- (V2*V2-V1*V1)/ (V1*V1-V2*V2)*(u1*u1-u2*u2)*(Vr2*Vr2-Vr1*Vr1)
Explanation: This is obtained by substituting mathematical terms in actual expression of degree of reaction.
Where, V=jet velocity, Vr=relative velocity, u=blade velocity
10. Degree of reaction for reaction turbine is _____________
a) 1- cot x /2(cot x –cot y)
b) 1+ cot x /2(cot x –cot y)
c) 1- cot x /2(cot x +cot y)
d) 1+ cot x /2(cot x +cot y)
Explanation: Because for reaction turbine Vw2=0 and V2=Vf2, there is also no much change in velocity of flow implies that Vf1=Vf2 by substituting these values, we get it