Steam at 14 bar and 250°C enters a convergent-divergent steam nozzle and is discharged at 2 bar. Determine the nozzle efficiency if the velocity coefficient is 0.95. Neglect the initial velocity of steam.

Dry and saturated steam at 11 bar pressure enters a convergent-divergent nozzle and is discharged at 2 bar. Determine the actual enthalpy drop if he efficiency of the nozzle is 96%.

A

254.56 kJ/kg

B

321.32 kJ/kg

C

288.14 kJ/kg

D

245.63 kJ/kg

The velocity of steam leaving the nozzle (V) is given by (where K = Nozzle coefficient or nozzle efficiency, and hd = Enthalpy or heat drop during expansion of steam in a nozzle)

A

V = 44.72 hd K

B

V = 44.72 K hd

C

V = 44.72 K hd

D

V = 44.72 K hd

The velocity of steam leaving the nozzle (V) is given by (where K = Nozzle coefficient or nozzle efficiency and h_d = Enthalpy or heat drop during expansion of steam in a nozzle)

A

V = 44.72 $${{\text{h}}_{\text{d}}}\sqrt {\text{K}} $$

B

V = 44.72 $${\text{K}}\sqrt {{{\text{h}}_{\text{d}}}} $$

C

V = 44.72$$\sqrt {{\text{K}}{{\text{h}}_{\text{d}}}} $$

D

V = 44.72 $${\text{K}}{{\text{h}}_{\text{d}}}$$

Seven contestants, H, I, J, K, L, M and N, have their entry on stage at the Miss World contest in a certain sequence. I enters exactly before M. J enters exactly after N. Exactly one contestant enters on stage after M and before H in the same order. L enters third. H enters last. Based on the given information, which of the following options is true?

A

L enters after M

B

J enters fourth in number

C

N enters first in number

D

I enters fifth in number

Determine the exit pressure of steam if the steam enters a nozzle at 11 bar and 300°C. At the outlet it is observed that the specific volume of the steam is 0.86804 m3/kg. The expansion of steam is metastable.

A

4 bar

B

3 bar

C

2 bar

D

1 bar

Steam issues from the nozzle with a velocity of 1000 m/s in a De Laval turbine. The nozzle angle is 20°, mean blade velocity is 350 m/s. The inlet and outlet angles of the blades are equal. The mass of the steam flowing through the turbine per second is 0.3 kg. Calculate the tangential force on the blades. Take blade velocity coefficient as 0.8.

A

451 N

B

256 N

C

318 N

D

196 N

A simple impulse turbine has a mean blade speed of 250 m/s. The nozzle angle is 20° and the steam velocity from the nozzle is 600 m/s. The turbine uses 3000 kg/h of steam. The blade outlet angle is 25°. Determine the amount of energy converted to heat by blade friction if the blade friction factor is 0.86.

A

65.32 kJ

B

30.50 kJ

C

45.32 kJ

D

78.32 kJ

In a single row impulse turbine, the absolute velocity of steam leaving the turbine is 900 m/s. The nozzle angel is 20°. The mean blade speed is 300 m/s. The inlet blade angle is equal to the outlet blade angle. Determine the angle made by the discharging steam with the tangent of the wheel at the exit of moving blade. Neglect friction on turbine blades.

A

27°

B

36°

C

51°

D

90°

In a single row impulse turbine, steam leaves the nozzle at 600 m/s. The nozzle angle and the mean blade speed is 25° and 200 m/s. The blade velocity coefficient is 0.8. Determine the blade outlet angle if the steam leaves the turbine blades axially.

A

54°

B

60°

C

66°

D

74°

Determine the pan evaporation from the following data using the Christiansen method. Extra-terrestrial radiation in cm = 47.3cm Coefficient of temperature(Ct) = 1.403 Coefficient for wind velocity (Cw)= 1.2 Coefficient for relative humidity (Ch) = 1 Coefficient for percent of possible sunshine(Cs) = 1.073 Coefficient of elevation(Ce) = 1.014

A

40 cm

B

30.44 cm

C

39.8 cm

D

37.98 cm

Steam at 14 bar and 250°C enters a convergent-divergent steam nozzle and is discharged at 2 bar. Determine the nozzle efficiency if the velocity coefficient is 0.95. Neglect the initial velocity of steam.

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