Questions and answers for exam Preparation

MCQs

Total Questions : 304 | Page 5 of 31 pages

Question 41. An impulse turbine is used for

low head of water
high head of water
medium head of water
high discharge

Discuss Question

Answer: Option B. -> high head of water
Answer: (b).high head of water

Question 42. Which type of the pump is different from others in the same group?

Screw pump
Gear pump
Cam and piston pump
Plunger pump

Discuss Question

Answer: Option D. -> Plunger pump
Answer: (d).Plunger pump

Question 43. Power required to drive a centrifugal pump is __________ proportional to N3.

directly
inversely
Can't say
None of these

Discuss Question

Answer: Option A. -> directly
Answer: (a).directly

Question 44. The efficiency of jet propulsion for a ship with inlet orifices at right angles to the direction of motion of ship, will be maximum when the relative velocity of the jet and ship is equal to twice the velocity of the ship.

Yes
No
Can't say
None of these

Discuss Question

Answer: Option A. -> Yes
Answer: (a).Yes

Question 45. The cavitation in reaction turbines is avoided, to a great extent by

installing the turbine below the tail race level
using stainless steel runner of the turbine
providing highly polished blades to the runner
all of the above

Discuss Question

Answer: Option D. -> all of the above
Answer: (d).all of the above

Question 46. The force exerted (in newton) by a jetof water impinging normally on a fixed plate is (where w = Specific weight of water in N/m³, a = Cross-sectional area of jet in m², and V = Velocity of jet in m/s)

waV / 2g
waV / g
waV² / 2g
waV² / g

Discuss Question

Answer: Option D. -> waV² / g
Answer: (d).waV² / g

Question 47. Delivery head of a centrifugal pump is

directly proportional to N
inversely proportional to N
directly proportional to N²
inversely proportional to N²

Discuss Question

Answer: Option C. -> directly proportional to N²
Answer: (c).directly proportional to N²

Question 48. The power developed by a turbine is (where H = Head of water under which the turbine is working)

directly proportional to H^1/2
inversely proportional to H^1/2
directly proportional to H^3/2
inversely proportional to H^3/2

Discuss Question

Answer: Option C. -> directly proportional to H^3/2
Answer: (c).directly proportional to H^3/2

Question 49. If V1 and V2 are the velocities of water at inlet and outlet of the draft tube respectively, then the efficiency of a draft tube is

(V1 - V2) / V1
(V1² - V2²) / V1²
V1 / (V1 - V2)
V1² / (V1² - V2²)

Discuss Question

Answer: Option B. -> (V1² - V2²) / V1²
Answer: (b).(V1² - V2²) / V1²

Question 50. A Pelton wheel develops 1750 kW under a head of 100 metres while running at 200 r.p.m. and discharging 2500 litres of water per second. The unit discharge of wheel is