# A bar is subjected to fluctuating tensile load from 20 KN to 100 KN. The material has yield strength of 240 MPa and endurance limit in reversed bending is 160 MPa. According to the soderberg principle, the area of cross-section in mm2 of the bar for a factor of safety of 2 is

1.  400

2.  600

3.  750

4.  1000

4

1000

Explanation :
No Explanation available for this question

# Weldments in fabricated steel beams are designed for

1.  Bending stresses at the flange

2.  Shear stresses in transverse plane

3.  Combination of bending and shear

4.  None of these because in fabricated beams welds do not get stressed

4

Combination of bending and shear

Explanation :
No Explanation available for this question

# For full depth of involute spur gears, minimum number of teeth of pinion to avoid interference depends upon

1.  Pressure angle

2.  Speed ratio

3.  Circular pitch

4.  Pitch diameter

4

Pressure angle

Explanation :
No Explanation available for this question

# Modern gear tooth profile is given involute shape because

1.  This is very easy curve for manufacturing

2.  Sliding does not takes place

3.  Involute is the only profile that gives conjugate action

4.  Change in the centre distance does not change gear ratio

4

Change in the centre distance does not change gear ratio

Explanation :
No Explanation available for this question

# Tooth interference in an external involute spur gear pair can be reduced by

1.  Decreasing center distance between gears

2.   Decreasing module

3.   Decreasing pressure angle

4.  Increasing number of teeth

4

Increasing number of teeth

Explanation :
No Explanation available for this question

# In order to test the efficiency of reducer gear train 1KW input was given at the input end at a speed of 1440 RPM and at the output end the measured torque was 56.36N.m. If the ratio of speed reduction in this  unit is 10:1, the efficiency is about

1.  78%

2.   85%

3.  63%

4.   96%

4

85\%

Explanation :
No Explanation available for this question

# The expected life of a ball bearing subjected to a load of 9800N and working at 1000RPM. is 3000hours what is the expected life of the same bearing for a similar load of 4900 N and a speed of 2000rpm

1.  Unchanged

2.  12,000 hours

3.  1,500 hours

4.  6,000 hours

4

12,000 hours

Explanation :
No Explanation available for this question

# If the load on a ball bearing is reduced to half, the life of the ball bearing will

1.   Increase 8 times

2.  Increase 4 times

3.  Increase 2 times

4.  Not change

4

Increase 8 times

Explanation :
No Explanation available for this question

1.  a-u, b-q, c-r, d-t

2.  a-u, b-q, c-t, d-r

3.  a-v, b-q, c-r, d-r

4.  a-v, b-u, c-r, d-r

4

a-u, b-q, c-r, d-t

Explanation :
No Explanation available for this question

# Spherical roller bearings are normally used

2.  For increased thrust load

3.  When there is less radial load

4.  To compensate for angular misalignment

4