Model Questions for SSC Junior Engineer EXAM - Mechanical Engg Set-6

1. The specific speed of a centrifugal pump, delivering 750 litres of water per second against a head of 15 metres at 725 r.p.m., is

A. 82.4 r.p.m.
B. 48.2 r.p.m
C. 24.8 r.p.m.
D. 248 r.p.m

2. Which of the following turbine is preferred for 0 to 25 m head of water?

A. Francis turbine
B. Kaplan turbine
C. Pelton wheel
D. none of these

3. Multi-stage centrifugal pumps are used to

A. give high discharge
B. pump viscous fluids
C. produce high heads
D. all of these

4. Which of the following pump is preferred for flood control and irrigation applications?

A. Mixed flow pump
B. Reciprocating pump
C. Axial flow pump
D. Centrifugal pump

5. Discharge of a centrifugal pump is (where N = Speed of the pump impeller)

A. directly proportional to N
B. inversely proportional to N2
C. directly proportional to N2
D. inversely proportional to N

Study Kit for SSC Junior Engineer EXAM (Paper-1) 2017-2018

6. Theoretical power required (in watts) to drive a reciprocating pump is (where w = Specific weight of liquid to be pumped in N/m3, Q = Discharge of the pump in m3/s, Hs = Suction head in metres, and Hd = Delivery head in metres)

A. wQHs
B. wQ(Hs + Hd)
C. wQHd
D. wQ(Hs - Hd)

7. In a reaction turbine, the draft tube is used

A. to increase the head of water by an amount equal to the height of the runner outlet above the tail race
B. to prevent air to enter the turbine
C. to transport water to downstream
D. to run the turbine full

8. The speed of a turbine runner is

A. inversely proportional to H1/2
B. directly proportional to H3/2
C. directly proportional to H1/2
D. inversely proportional to H3/2

9. Slip of a reciprocating pump is defined as the

A. product of theoretical discharge and the actual discharge
B. sum of actual discharge and the theoretical discharge
C. ratio of actual discharge to the theoretical discharge
D. difference of theoretical discharge and the actual discharge

10. Geometric similarity is said to exist between the model and the prototype, if both of them

A. are identical in shape, but differ only in size
B. have identical forces
C. are equal in size and shape
D. have identical velocities

Study Kit for SSC Junior Engineer EXAM (Paper-1) 2017-2018

Answer

1. (A) 2. (B) 3. (C) 4. (C) 5. (A) 6. (B) 7. (A) 8. (C) 9. (D) 10. (A)