ISRO Technical Assistant Mechanical Question Paper

ISRO Technical Assistant Mechanical Question Paper - 2019 with Answer Key

41) The heat that must be absorbed by ice of mass 500g at (-10 degree centigrade) to take it to water at 20 degree centigrade is (specific heat of ice is 2.2 kJ/kgK, specific heat of water is 4.2 kJ/kgK and Latent heat of fusion of ice is 300 kJ/kg)

Answer is:

203 kJ

42) Which of the processes gives the least surface roughness?

Answer is:

lapping

Explanation:

Lapping is a machining process in which two surfaces are rubbed together with an abrasive between them, by hand movement or using a machine. Lapping process gives best surface finish.

Which of the processes gives the least surface roughness?

43) Which of the following material cannot be machined by EDM?

Answer is:

Glass

44) When a dimension is specified as 20mm +0.0200/-0.010, the tolerance provided is

Answer is:

30 microns

45) Lower critical temperature of steel is

Answer is:

723 degree centigrade

Explanation:

The lower critical temperature is same for all steels Lower critical temperature for steel’s austenite-to-pearlite transformation is 1333 ºF (723 ºCelsius). Below this temperature, austentite doesn’t exist.