ISRO Scientist/Engineer SC Mechanical 2016

What will be answer of 1 & 2 ..?

Cutting speed of the tool in a mechanical shaper is

  • Max at middle of the cutting stroke
  • Max at beginning of the cutting stroke
  • Max at end of the cutting stroke
  • Min at middle of the cutting stroke

0 voters

creep is more in

  • blades of steam turbine
  • blades of gas turbine

0 voters

tungsten in high speed steel provides? 

  • hot heardness
  • sharp cutting edge
  • wear resistance
  • toughness

0 voters

guys any one know that how they will short list the candidate for exam?

Calculator allowed or not?

Anyone has 2015 corrected answer key

Guys how important is industrial engineering? Ang Imp topics in it?

The center of mohr circle always lies on 'X-Axis'

Radius of mohr circle = Max shear stress

Every oblique plane passing through a point is represented in the mohr circle  by a 'Radial Line' (possible radial lines = infinite)

Every place in mohr circle is represented by an angle 'Double' the actual angle

Coordinate of any point on the mohr circle will represent the corresponding 'Normal & Shear Stress' on that corresponding oblique plane

Principal planes are indicated by radial lines which are lying on the 'X-Axis' and the maginitude of the principal stresses = X-coordinate of POI (point of intersection) of mohr circle and 'X-Axis'

Maximum shear stress plane are parallel to 'Y-Axis'

Planes of pure shear, are the radial lines passing through the POI of 'Y-Axis' and the mohr circle

Resultant stress is the length of the line which is joining the coordinate on the mohr circle and the origin



For quietness operation of gears pressure angle should be

  • Between 20 to 14.5 degree
  • 20 degree
  • 25 degree
  • 14.5 degree

0 voters

The state of stress at a point 'P' in a 2-d loading is such that the mohr circle is a point located at 175 Mpa on positive normal stress axis.

1)Max and Min principal stresses respectively are 

a) +175 Mpa, -175 Mpa

b) +175 Mpa, +175 Mpa

c) 0, 0

d)none

2)The direction of Max and Min principal stresses at the point from the mohr circle are

a) 0, 90 degrees

b) 90, 0 degrees

c) 45, 135 degrees

d) All directions

For a Rectangular Notch and Wier: 

For every 1% error in head 'H' there will be 1.5% error in discharge 'Q'

For a Triangular Notch and Wier:

For every 1% error in head 'H' there will be 2.5% error in discharge 'Q'

Shape of spruce is conical

Shape of riser is cylindrical

Shape of runner is rhombus

Core is used for making hollow cavities in casting

Chills are metallic objects placed in the mould to increase the cooling rate of castings

The actual entry point through which the molten metal enters the mould cavity is gate

Pattern is  a replica of the final object made with some modifications

Pouring basin reduces the eroding force of the liquid metal stream

Skimbob is a trap placed in horizontal gate to prevent heavier and lighter impurities from entering the mould cavity

Liquid Shrinkage is the reduction in volume of the molten metal when it is being cooled from pouring temperature to freezing temperature. The volume can be compensated using riser.

Solid shrinkage is the reduction of volume when the metal looses its temperature in solid state.  Eg: shrinkage allowance of steel is 21mm/m

The inner details of the pattern require more draft allowance than the outer details

Shake allowance is a negative allowance

Last year ISRO ques.

The probability that  teacher will give a unannounced test is 1/5. If a student is absent twice, then probability that misses atleast one test is.  A.2/3  B.4/5 c.7/25 d. 9/25

In case of moulding sand; ramping if done too hard leads to prevention of gases escaping, if done too loose leads to loss of strength 

What is hyperbolic process

Calculate the permeability number of sand if it takes 1min 25 sec to pass 2000 cm^3 of air at a pressure of 5 g /cm^2 through the standard sample.

Ques no 30 solve kar do koi?? Photo ulta keech liya hai. Sorry for inconvenience. ..

Increase in 'grain fineness number' ->Permeability dec Strength inc 

Increase in 'clay content' ->Permeability dec Strength inc

Increase in 'degree of ramping' ->Permeability dec Strength inc

Increase in 'moisture content' ->Permeability and strength both Inc reaches max and then decreases