ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2014
For the following questions answer them individually
Two crossed helical gears are used for speed reduction. Gear A haspitch circle diameter in the plane of rotation 80mm and helix angle 30 deg; Gear B . Gear A haspitch circle
diameter in the plane of rotation 120mm andhelix angle 22.5 deg; If the input speed is 1440 RPM, then output speed in RPM is
In an arc welding process, the voltage and current are 25 V and 300 A respectively. The are heat transfer efficiency is 0.85 and welding speed is 8mm/sec. the net heat input (in J/mm) is:
Threaded bolts of A and B of same material and length are subjected to identical tensile load. If the elastic strain energy stored in bolt A is 4 times that of bolt B and the mean diameter of bolt A is 12mm, then mean diameterof bolt B is
In a condenser of a power plant, the steam condenses at a temperature of 333 K. The cooling water enters at 303 K and leaves at 318 K. The logarithmic mean temperature
difference (LMTD)of the condenser is
The shear strength of a sheet metal is 300 Mpa. The blanking force required to produce a blank of 100 mm diameter from a 1.5mm thick sheet is
