# JNTU Question Papers

## Prime Movers and Mechanical Measurements 1st Sem Nov 2008

1. (a) State and explain the applications of Momentum equation.

(b) A jet of water of diameter 6 cm strikes a flat plate held normal to the direction of jet with a velocity of 12 m / sec. What is the force exerted on the plate if it is stationary and what will be the work done. [8+8]

2. (a) What is the hydraulic function of a air vessel?

(b) A single acting reciprocating pump without air vessel has a plunger of 8cm diameter and a stroke of 12cm.It draws water from a sump 3m below the pump through a suction pipe 3 cm diameter and 5m long. It delivers water to a tank 12m above the pump through a delivery pipe 2cm diameter and 15m long. If separation occurs at a pressure of 67 KN /m2 below atmospheric pressure, find the maximum speed at which the pump may be operated without separation.

[6+10]

3. Draw the neat diagram of hyperbolic cooling tower and discuss its merits and demerits. [16]

4. (a) List the advantages and limitations of velocity compounding of steam engines.

(b) In an impulse turbine, the steam enters at a velocity of 400 m/sec. The nozzle angle is 120. Assuming optimum blade speed, find the blade inlet angle. If the steam leaves the blades axially at the exit, find the blade outlet angle also find the blade efficiency. [6+10]

5. A gas turbine draws air at atmospheric pressure and 299 K. There are two stages of compression with an intercooler and the pressure ratio is 8:1 in each stage. The maximum temperature of the cycle is 800 K. Determine the thermal efficiency and work ratio if efficiency of turbine and compressor are 0.86 and 0.83 respectively.

[16]

6. Explain with neat sketches the principle differences between the measuring devices used for Translational, Relational and Angular Velocity measuring devices. [16]

7. (a) Define mass standard.

(b) Explain the principle of variable reluctance pickup used in the measurement of vibration.

(c) Explain how a proving ring is used to measure force. [4+8+4]

8. (a) Describe the construction and working of a water vortex dynamometers. What are the reasons for its popularity?

(b) A hydraulic dynamometer has been used to absorb 10KW. The quantity of water flowing through the dynamometer is 10kg/min. Assuming that there is no loss of energy to surroundings, calculate the rise in temperature of water.

JNTU Prime Movers and Mechanical Measurements Question Paper Nov 2008