  # ISRO Scientist or Engineer Mechanical 2018

Instructions

For the following questions answer them individually

Question 11

# The specific speed of a centrifugal pump, delivering 1000litres of water per second against a head of 16 meter at 800 rom Question 12

# A pipe of 0.1 m$$^2$$ suddenly changes to 0.5 m$$^2$$ area. The quantity of water flowing in the pipe is 0.5 m$$^3$$/s. Head loss due to sudden enlargement is nearly Question 13

# Efficiency of a centrifugal pump is maximum when the blades are Question 14

# The critical radius of insulation for a spherical shell is Question 15

# If the temperature of a solid surface changes from $$27^circ C$$ to $$81^circ C$$, then its emissive power changes in the ratio of nearly Question 16

# The heat removal rate from a refrigerated space is 7.2 kW and the power input to the compressor is 1.8 kW. The coefficient of performance (COP) of the refrigerator is Question 17

# For a fluid having Prandtl number equal to unity, the relation between hydrodynamic boundary layer thickness ($$\delta_1$$) and thermal boundary layer thickness ($$\delta_2$$) Question 18

# Life of a ball bearing at a load of 10 kN is 24000 hours. If the load is increased to 20 kN (all other conditions are same), its life in hour is Question 19

# The impact strength of a material is an index of its Question 20

# Which of the following order of crystal structure will match with metals lron-Nickel Titanium in that order at room temperature? OR