Page 91 - CITS - WCS - Mechanical

WORKSHOP SCIENCE - CITS

= 200 x 0.0005
= 0.1 cm
\ Elongated length = 0.1 cm

Stress

1 Calculate the intensity of stress in the material if a copper rod of 40 mm diameter is subjected by tensile load
of 4000 Newton’s.
2 Calculate the intensity of stress if a mild steel rod having a cross sectional area of 40 mm is subjected to the
2
load of 1000 kg.
3 Calculate the tensile stress if a square rod of 10 mm side is tested for a tensile load of 1000 kg.
4 Calculate the maximum stress if a bar of 9 cm cross sectional area 300 cm long carries a tensile load of 3500
2
kg.
5 Find out the stress on the rod. if a load of 500 kg is placed on a M.S.rod of dia. 35 mm.
6 A metallic bar of 8 cm diameter is under stress carrying a load of 8620 N. Calculate the intensity of stress.
7 A steel wire 2 mm diameter is loaded in tension with a weight of 20 kg. Find out the stress developed.

8 A rod having a cross sectional area of 25 mm is subjected to a load of 1500 kg. Find out stress on the rod.
2
9 A square rod of 10 mm side is tested for a tensile load of 2500 kg. Calculate the tensile stress of the rod.
Strain
1 Find the compressive strain if a metal bar is 150 cm long. When 2.5 KN is applied, its length becomes 148.6
cm.
2 Calculate the strain if a metallic bar is 150 cm long. When 2500 kg is applied its length becomes 150.5 cm.
3 Find the strain it causes if a load of 300 kg hanging from a rod of 3 metres length and 5 mm diameter extends
it by 4 mm.
4 A tensile force of 10 kg is applied on a copper wire of diameter 1 cm. So that the length of wire increases by
5 mm. If the original length of wire was 2 metres, find out the strain.

5 A steel rod whose diameter is 1 cm and 60 cm in length. This rod is pulled at both ends by a force of 700 kg.
If modulus of elasticity of steel is 2.1 ×10 kg/cm , find out increase in length of rod and strain produced in it.
2
6
6 A steel rod 1.5 metres long and of 30 mm diameter is pulled at both ends by a force of 1500 kg. If modulus of
elasticity of steel is 2.4 ×10 kg/cm , determine increase in length of rod and strain produced in it.
2
6
7 Calculate the change in length of a rod of dia 16 mm and 160 mm long when it carries a load of 40KN. Take E
= 200000 N/mm .
2
8 A hollow C.I. column with a wall thickness of 2 cm is subjected to an axial compressive load of 80 tonnes. If the
maximum stress is not to be exceeded 1 tonne per cm , determine the internal diameter of column. Calculate
2
compressive strain, if E = 950 tonnes per cm .
2
Young’s modulus
1 A piece of wire 2 m long, 0.8 mm in cross section increases its length by 1.6 mm on suspension of 8 kg weight
2
from it. Calculate the stress, strain and young’s modulus.
2 A wire of 16 mm dia. is subjected to a tensile load of 2000 kg. Find the stress and strain if young’s modulus E
= 2 x 10 kg/cm .
16
2
3 A wire is of 2 metres long and its area of cross section is 0.78 mm . If 78 kg weight is suspended on this wire,
2
then the length of the wire is increased by 1.4 mm. Find out stress, strain and young’s modulus of elasticity.
4 A wire 2800 mm long is stretched by 0.5 mm, when a weight of 9 kg is hung on it, its diameter is 2 mm. Calculate
stress and young’s modulus for the substance of the wire.

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CITS : WCS - Mechanical - Exercise 7