Power Engineering 3A1 Exam Questions With Complete
Solutions
A steel rod 3 m long has a cross-sectional area of 26 cm2 and is
stretched 0.05 cm by a load suspended from one end. Young's
modulus is 210 X 106kPa. What is the stress produced by the
load?
a. 35 kPa
A steel rod 3 m long has a cross-sectional area of 0.26 m2 and is
stretched 0.05 cm by a load suspended from one end. The stress
produced by the load is 350 kPa. Young's modulus is 210 X 106.
What is the load?
d. 91000 N
A steel rod has a factor of safety of 4.3. The maximum stress on
the rod is 5431 kPa. What is the ultimate strength of the steel
rod.
b. 23353.3 kPa
A steel rod is 100 cm long and is subjected to a load of 10,000
N. While subjected to this load the length of the bar remains the
same. Young's modulus is 306 GPa. Determine the strain on the
bar.
d. 0
A steel rod is 5 m long and has a cross-sectional area of 0.26
m2. When subjected to a load of 1421 N the rod is stretched
to .0012 m. What is Young's modulus for this material?
,b. 22.772 MPa
If the factor of safety of a piston under a working load of 800
KN is
7.85 what is the diameter of the piston if the ultimate strength of
the material is 800,000 kPa.
a. 10 cm
A 2.5 cm diameter bolt is in double shear and carries a load of
30 KN. What is the shear stress in the bolt?
d. 30,559 kPa
Hook's Law applies to the portion in the stress-strain diagram
where the curve representing the relationship between the stress
and strain is:
b. Linear
According to Hooke's Law, the stress in an elastic body is
directly proportional to the strain if:
e. The elastic limit is not exceeded
In the equation where, E is known as the modulus of elasticity or
.
d. the Young's modulus
The yield point for a material is the point at which it undergoes
large deformation at a
d. Constant stress
,The ultimate stress of a material is determined by the
experimental test. The ultimate stress of a material can be
calculated according to the following:
e. Dividing the maximum load by the original cross-sectional
area of the test sample.
If a material is stressed beyond the proportional limit and does
not totally regain its original shape when the stress is removed,
the amount of deformation is called:
c. Strain
A hole 12 mm in diameter is to be punched through a plate 18
mm thick. If the shear strength of the material is 300 N/mm2,
find the load required on the punch.
d. 203.6 KN
The ratio of shear stress to shear strain is called the modulus
rigidity (G). It is also known as the:
c. Young's modulus
A tie bar made of mild steel of tensile strength 462 MN/m2 is to
carry a tensile load of 11.12 KN, find its diameter allowing a
factor of safety of 12.
a. 19.17 mm
Safe working stress is determined by:
c. Dividing the ultimate stress by the factor of safety
A safe load of 20.31 KN is carried by a stud of 580.2 mm2 in
cross- sectional area at the bottom of the thread. The bolt has a
, safe working stress of 35 MN/m2. Calculate the number of studs
required to hold the cylinder cover of a diesel engine where the
maximum pressure in the cylinder is 42 X 105 N/m2 and the
diameter of the cover is 380 mm.
e. 24
The ratio of the output force to the input force is called the:
a. Actual mechanical advantage
Velocity ratio is:
e. Ideal mechanical advantage
The efficiency of any apparatus is given by the ratio:
c. Output divided by input
Load multiplied by distance load moves divided by effort
multiplied by distance effort moves is the:
c. Efficiency of a simple machine
Actual mechanical advantage divided by velocity ratio is equal
to:
a. Efficiency
A solid brass statue has a mass of 20 000 kg. What mass of steel
would be required to exactly duplicate the structure?
b. 18 738 kg
A solid cylinder is 31 cm dia. by 2.4 m long. It has the same
mass as a lead cube with 0.5 m sides. What material is the
cylinder likely made of?
Solutions
A steel rod 3 m long has a cross-sectional area of 26 cm2 and is
stretched 0.05 cm by a load suspended from one end. Young's
modulus is 210 X 106kPa. What is the stress produced by the
load?
a. 35 kPa
A steel rod 3 m long has a cross-sectional area of 0.26 m2 and is
stretched 0.05 cm by a load suspended from one end. The stress
produced by the load is 350 kPa. Young's modulus is 210 X 106.
What is the load?
d. 91000 N
A steel rod has a factor of safety of 4.3. The maximum stress on
the rod is 5431 kPa. What is the ultimate strength of the steel
rod.
b. 23353.3 kPa
A steel rod is 100 cm long and is subjected to a load of 10,000
N. While subjected to this load the length of the bar remains the
same. Young's modulus is 306 GPa. Determine the strain on the
bar.
d. 0
A steel rod is 5 m long and has a cross-sectional area of 0.26
m2. When subjected to a load of 1421 N the rod is stretched
to .0012 m. What is Young's modulus for this material?
,b. 22.772 MPa
If the factor of safety of a piston under a working load of 800
KN is
7.85 what is the diameter of the piston if the ultimate strength of
the material is 800,000 kPa.
a. 10 cm
A 2.5 cm diameter bolt is in double shear and carries a load of
30 KN. What is the shear stress in the bolt?
d. 30,559 kPa
Hook's Law applies to the portion in the stress-strain diagram
where the curve representing the relationship between the stress
and strain is:
b. Linear
According to Hooke's Law, the stress in an elastic body is
directly proportional to the strain if:
e. The elastic limit is not exceeded
In the equation where, E is known as the modulus of elasticity or
.
d. the Young's modulus
The yield point for a material is the point at which it undergoes
large deformation at a
d. Constant stress
,The ultimate stress of a material is determined by the
experimental test. The ultimate stress of a material can be
calculated according to the following:
e. Dividing the maximum load by the original cross-sectional
area of the test sample.
If a material is stressed beyond the proportional limit and does
not totally regain its original shape when the stress is removed,
the amount of deformation is called:
c. Strain
A hole 12 mm in diameter is to be punched through a plate 18
mm thick. If the shear strength of the material is 300 N/mm2,
find the load required on the punch.
d. 203.6 KN
The ratio of shear stress to shear strain is called the modulus
rigidity (G). It is also known as the:
c. Young's modulus
A tie bar made of mild steel of tensile strength 462 MN/m2 is to
carry a tensile load of 11.12 KN, find its diameter allowing a
factor of safety of 12.
a. 19.17 mm
Safe working stress is determined by:
c. Dividing the ultimate stress by the factor of safety
A safe load of 20.31 KN is carried by a stud of 580.2 mm2 in
cross- sectional area at the bottom of the thread. The bolt has a
, safe working stress of 35 MN/m2. Calculate the number of studs
required to hold the cylinder cover of a diesel engine where the
maximum pressure in the cylinder is 42 X 105 N/m2 and the
diameter of the cover is 380 mm.
e. 24
The ratio of the output force to the input force is called the:
a. Actual mechanical advantage
Velocity ratio is:
e. Ideal mechanical advantage
The efficiency of any apparatus is given by the ratio:
c. Output divided by input
Load multiplied by distance load moves divided by effort
multiplied by distance effort moves is the:
c. Efficiency of a simple machine
Actual mechanical advantage divided by velocity ratio is equal
to:
a. Efficiency
A solid brass statue has a mass of 20 000 kg. What mass of steel
would be required to exactly duplicate the structure?
b. 18 738 kg
A solid cylinder is 31 cm dia. by 2.4 m long. It has the same
mass as a lead cube with 0.5 m sides. What material is the
cylinder likely made of?
