61. A turbine is called impulse if at the inlet of the turbine

- Total energy is only kinetic energy
- Total energy is only pressure energy
- Total energy is the sum of kinetic energy and pressure energy
- None of the above

62. For high head, the suitable turbine is

- Pelton
- Francis
- Kaplan
- None of the above

63. Muschel curves belong to the category of

- main characteristic curves of a turbine
- operating characteristic curves of a turbine
- constant efficiency curves of a turbine
- operating characteristics of a pump

64. Which of the following statements is correct?

- Pelton wheel is reaction turbine
- Pelton wheel is a radial flow turbine
- Pelton wheel is an impulse turbine
- None of the above

65. If the energy present in a jet of water of 20 cm diameter and having a velocity of 25 m/s could be extracted by a device with 90% efficiency, the power extracted would be nearly

(taking 1/2g = 0.051 sec^{2}/m)

- 180 kW
- 225 kW
- 260 kW
- 300 kW

66. The work done by a kN of water jet moving with a velocity of 60 m/sec when it impinges on a series of vanes moving in the same direction with a velocity of 9 m/sec is

- 55.6 kNm
- 45.0 kNm
- 60.2 kNm
- 46.8 kNm

67. Consider the following data from a test on Pelton wheel:

Head at the base of the nozzle = 32 m

Discharge of the nozzle = 0.18 m^{3}/s

Area of the jet = 7500 mm^{2}

Power available at the shaft = 44 kW

Mechanical efficiency = 94%

The power lost in the nozzle will be nearly

- 4.7 kW
- 3.9 kW
- 2.3 kW
- 3.5 kW

68. A jet of water coming out of a nozzle with velocity 50 m/s is having cross sectional area of 20 cm^{2}. The jet is directed against a fixed flat plate held normal to the jet. Find the force exerted on the plate.

- 5000 N
- 2000 N
- 5000 kN
- 200 N

69. If ‘v_{1}‘is the velocity of jet at inlet and ‘u’ is the tangential velocity of vane, for maximum efficiency of Pelton Wheel the condition is

- u = v
_{1}/4 - u = v
_{1}/2 - u = v
_{1} - 2u= v
_{1}

70. In the Pelton wheel turbine, the formula to find the number of buckets (Z) on a runner is (where D = pitch diameter of the pelton wheel, d = diameter of the jet):

- Z = 15 + D/2d
- Z = 20 + D/d
- Z = 15 + D/3d
- Z = 15 + D/d