ABSA-4th Class- Power Engineering-
Part A Exam Questions and All
Complete Answers.
Velocity (m/s) - Answer Change in position / time
Acceleration (m/s^2) - Answer Change in velocity (m/s) / time (s)
Force (Newton) - Answer mass (kg) x acceleration (m/s^2) , any action on a body that tends
to change its size, shape, or its state of rest or motion
Force of Gravity - Answer mass (kg) x 9.81 m/s^2
Pressure (Pa) - Answer Force (N) / area (m^2)
Work (J) - Answer Force (N) x distance (m)
Power - Answer Work done / time , Rate of doing work
Potential Energy (J) - Answer mass x gravity x height , the ability of a body to do work due by
virtue of its position
Kinetic Energy (J) - Answer 1/2 x mass x velocity^2 , The ability of a body to do work due to
its motion
Energy (J) - Answer The capacity of a body to do work
Tonne - Answer 1000 kilograms
Moment of Force (Nm) - Answer Force (N) x Distance (m) , A force, acting on a body at any
distance from a point on that body, will tend to produce rotation around that point
Clockwise Moments - Answer Equal to Counter-clockwise moments
Upward Forces - Answer Equal to Downward forces
,Actual Mechanical Advantage (Ma) - Answer Load (N) / Effort (N)
Velocity Ratio (VR) - Answer Distance moved by Effort / Distance moved by Load
Efficiency - Answer Output Work / Input Work
Output Work - Answer Load x Distance moved by load
Input Work - Answer Effort x Distance moved by effort , Equals Output work + Wasted work
Ideal Mechanical Advantage (MA) - Answer Equal to Velocity Ratio (VR)
Load x r - Answer Equal to Effort x R
VR - Answer Equal to R/r and D/d
Load /Effort - Answer Equal to R/r
Scalar - Answer A physical quantity that has magnitude but no direction
Vector - Answer A quantity that has magnitude and direction
Space Diagram - Answer Illustrates a system of vectors
Co-planar Vectors - Answer Vectors that are all in the same plane
Concurrent Vectors - Answer Vectors whose lines of action meet at one point
Resultant - Answer A vector that represents the sum of two or more vectors
Absolute Pressure - Answer Atmospheric pressure + gauge pressure
Static Friction - Answer A friction force that acts on objects that are not moving. Always
greater than kinetic friction
,Kinetic Friction - Answer Friction that opposes motion once the motion has already started.
Not affected by speed of body Always greater than rolling friction.
Rolling Friction - Answer The friction force that acts on rolling objects, Always less than
kinetic friction
Fluid Friction - Answer Friction that occurs as an object moves through a fluid
Force of Friction - Answer Force that resists motion when two materials are in contact.
Proportional to the force that presses the two surfaces together. Not affected by area. Affected
by roughness.
Elasticity - Answer The ability of a material to return to its original shape after being
disturbed
Stiffness - Answer Ability of a material to resist a change in shape or size when a load is
applied
Plasticity - Answer Ability of a material to retain its deformed shape when a deforming force
is removed
Ductility - Answer Ability of a material to be stretched and reduced in cross section without
breaking
Toughness - Answer Ability of a material to absorb energy before breaking
Hardness - Answer Ability of a material to resist penetration
Stress - Answer Internal resistance to an external load , Equal to Load (N) / Area (m^2)
Tensile Stress - Answer Forces that act at opposite ends of a bar and pull away from each
other, creating tension on the bar
Compressive Stress - Answer A stress due to a force pushing together on a body
Shear Stress - Answer Forces on a bar that act parallel to another but are not on the same
plane
, Ultimate Stress - Answer The stress at which fracture of the material occurs
Allowable Stress - Answer The greatest stress which a material is capable of developing
without permanent deformation remaining upon the complete release of stress.
Elastic Limit - Answer Maximum stress that a material will withstand without permanent
deformation. Will return to its original size and shape
Factor of Safety - Answer Ultimate Stress / Allowable Stress
Strain - Answer A measure of the deformation produced in a member by a load , Equal to
Change in Length (l) / Original Length (L)
Circumferance - Answer pi x Diameter
Linear Speed - Answer Equal to rev/min x pi D / 60
Four States of Matter - Answer solid, liquid, gas, plasma
Phase - Answer One individual substance in one particular state
Chemical Properties - Answer Only observed when there is a chemical change or reaction ,
Examples are Heat of combustion, Toxicity, Flammability, Chemical Stability
Physical Properties - Answer Characteristics that you can observe without a change in the
composition of matter
Intensive Physical Property - Answer Not dependent on the amount of matter
Extensive Physical Property - Answer Dependent on the amount of matter
Mixture - Answer A combination of two or more substances that are not chemically
combined
Homogeneous Mixture - Answer AKA Solution , Only has one set of properties , Possible only
when all the components are in the same physical state , Ex. Flue gas
Part A Exam Questions and All
Complete Answers.
Velocity (m/s) - Answer Change in position / time
Acceleration (m/s^2) - Answer Change in velocity (m/s) / time (s)
Force (Newton) - Answer mass (kg) x acceleration (m/s^2) , any action on a body that tends
to change its size, shape, or its state of rest or motion
Force of Gravity - Answer mass (kg) x 9.81 m/s^2
Pressure (Pa) - Answer Force (N) / area (m^2)
Work (J) - Answer Force (N) x distance (m)
Power - Answer Work done / time , Rate of doing work
Potential Energy (J) - Answer mass x gravity x height , the ability of a body to do work due by
virtue of its position
Kinetic Energy (J) - Answer 1/2 x mass x velocity^2 , The ability of a body to do work due to
its motion
Energy (J) - Answer The capacity of a body to do work
Tonne - Answer 1000 kilograms
Moment of Force (Nm) - Answer Force (N) x Distance (m) , A force, acting on a body at any
distance from a point on that body, will tend to produce rotation around that point
Clockwise Moments - Answer Equal to Counter-clockwise moments
Upward Forces - Answer Equal to Downward forces
,Actual Mechanical Advantage (Ma) - Answer Load (N) / Effort (N)
Velocity Ratio (VR) - Answer Distance moved by Effort / Distance moved by Load
Efficiency - Answer Output Work / Input Work
Output Work - Answer Load x Distance moved by load
Input Work - Answer Effort x Distance moved by effort , Equals Output work + Wasted work
Ideal Mechanical Advantage (MA) - Answer Equal to Velocity Ratio (VR)
Load x r - Answer Equal to Effort x R
VR - Answer Equal to R/r and D/d
Load /Effort - Answer Equal to R/r
Scalar - Answer A physical quantity that has magnitude but no direction
Vector - Answer A quantity that has magnitude and direction
Space Diagram - Answer Illustrates a system of vectors
Co-planar Vectors - Answer Vectors that are all in the same plane
Concurrent Vectors - Answer Vectors whose lines of action meet at one point
Resultant - Answer A vector that represents the sum of two or more vectors
Absolute Pressure - Answer Atmospheric pressure + gauge pressure
Static Friction - Answer A friction force that acts on objects that are not moving. Always
greater than kinetic friction
,Kinetic Friction - Answer Friction that opposes motion once the motion has already started.
Not affected by speed of body Always greater than rolling friction.
Rolling Friction - Answer The friction force that acts on rolling objects, Always less than
kinetic friction
Fluid Friction - Answer Friction that occurs as an object moves through a fluid
Force of Friction - Answer Force that resists motion when two materials are in contact.
Proportional to the force that presses the two surfaces together. Not affected by area. Affected
by roughness.
Elasticity - Answer The ability of a material to return to its original shape after being
disturbed
Stiffness - Answer Ability of a material to resist a change in shape or size when a load is
applied
Plasticity - Answer Ability of a material to retain its deformed shape when a deforming force
is removed
Ductility - Answer Ability of a material to be stretched and reduced in cross section without
breaking
Toughness - Answer Ability of a material to absorb energy before breaking
Hardness - Answer Ability of a material to resist penetration
Stress - Answer Internal resistance to an external load , Equal to Load (N) / Area (m^2)
Tensile Stress - Answer Forces that act at opposite ends of a bar and pull away from each
other, creating tension on the bar
Compressive Stress - Answer A stress due to a force pushing together on a body
Shear Stress - Answer Forces on a bar that act parallel to another but are not on the same
plane
, Ultimate Stress - Answer The stress at which fracture of the material occurs
Allowable Stress - Answer The greatest stress which a material is capable of developing
without permanent deformation remaining upon the complete release of stress.
Elastic Limit - Answer Maximum stress that a material will withstand without permanent
deformation. Will return to its original size and shape
Factor of Safety - Answer Ultimate Stress / Allowable Stress
Strain - Answer A measure of the deformation produced in a member by a load , Equal to
Change in Length (l) / Original Length (L)
Circumferance - Answer pi x Diameter
Linear Speed - Answer Equal to rev/min x pi D / 60
Four States of Matter - Answer solid, liquid, gas, plasma
Phase - Answer One individual substance in one particular state
Chemical Properties - Answer Only observed when there is a chemical change or reaction ,
Examples are Heat of combustion, Toxicity, Flammability, Chemical Stability
Physical Properties - Answer Characteristics that you can observe without a change in the
composition of matter
Intensive Physical Property - Answer Not dependent on the amount of matter
Extensive Physical Property - Answer Dependent on the amount of matter
Mixture - Answer A combination of two or more substances that are not chemically
combined
Homogeneous Mixture - Answer AKA Solution , Only has one set of properties , Possible only
when all the components are in the same physical state , Ex. Flue gas
