4th Class Power
Engineering Part A Exam
2026 | Study Guide,
Practice Questions,
Answers, Rationales &
Exam Review | Complete
Ethics Study Guide
Updated 2026 Questions and Answers
100% Verified Exam Prep and Comprehensive
Rationales
Included
,Velocity (m/s) Change in position / time
Acceleration (m/s^2) Change in velocity (m/s) / time (s)
Force (Newton) 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 mass (kg) x 9.81 m/s^2
Pressure (Pa) Force (N) / area (m^2)
Work (J) Force (N) x distance (m)
Power Work done / time , Rate of doing work
Potential Energy (J) mass x gravity x height , the ability of a body to do work due by virtue of its position
Kinetic Energy (J) 1/2 x mass x velocity^2 , The ability of a body to do work due to its motion
Energy (J) The capacity of a body to do work
Tonne 1000 kilograms
Moment of Force (Nm) 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 Equal to Counter-clockwise moments
Upward Forces Equal to Downward forces
Actual Mechanical Advantage (Ma) Load (N) / Effort (N)
Velocity Ratio (VR) Distance moved by Effort / Distance moved by Load
Efficiency Output Work / Input Work
Output Work Load x Distance moved by load
Input Work Effort x Distance moved by effort , Equals Output work + Wasted work
Ideal Mechanical Advantage (MA) Equal to Velocity Ratio (VR)
Load x r Equal to Effort x R
VR Equal to R/r and D/d
Load /Effort Equal to R/r
Scalar A physical quantity that has magnitude but no direction
, Vector A quantity that has magnitude and direction
Space Diagram Illustrates a system of vectors
Co-planar Vectors Vectors that are all in the same plane
Concurrent Vectors Vectors whose lines of action meet at one point
Resultant A vector that represents the sum of two or more vectors
Absolute Pressure Atmospheric pressure + gauge pressure
Static Friction A friction force that acts on objects that are not moving. Always greater than kinetic
friction
Kinetic Friction Friction that opposes motion once the motion has already started. Not affected by
speed of body Always greater than rolling friction.
Rolling Friction The friction force that acts on rolling objects, Always less than kinetic friction
Fluid Friction Friction that occurs as an object moves through a fluid
Force of Friction 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 The ability of a material to return to its original shape after being disturbed
Engineering Part A Exam
2026 | Study Guide,
Practice Questions,
Answers, Rationales &
Exam Review | Complete
Ethics Study Guide
Updated 2026 Questions and Answers
100% Verified Exam Prep and Comprehensive
Rationales
Included
,Velocity (m/s) Change in position / time
Acceleration (m/s^2) Change in velocity (m/s) / time (s)
Force (Newton) 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 mass (kg) x 9.81 m/s^2
Pressure (Pa) Force (N) / area (m^2)
Work (J) Force (N) x distance (m)
Power Work done / time , Rate of doing work
Potential Energy (J) mass x gravity x height , the ability of a body to do work due by virtue of its position
Kinetic Energy (J) 1/2 x mass x velocity^2 , The ability of a body to do work due to its motion
Energy (J) The capacity of a body to do work
Tonne 1000 kilograms
Moment of Force (Nm) 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 Equal to Counter-clockwise moments
Upward Forces Equal to Downward forces
Actual Mechanical Advantage (Ma) Load (N) / Effort (N)
Velocity Ratio (VR) Distance moved by Effort / Distance moved by Load
Efficiency Output Work / Input Work
Output Work Load x Distance moved by load
Input Work Effort x Distance moved by effort , Equals Output work + Wasted work
Ideal Mechanical Advantage (MA) Equal to Velocity Ratio (VR)
Load x r Equal to Effort x R
VR Equal to R/r and D/d
Load /Effort Equal to R/r
Scalar A physical quantity that has magnitude but no direction
, Vector A quantity that has magnitude and direction
Space Diagram Illustrates a system of vectors
Co-planar Vectors Vectors that are all in the same plane
Concurrent Vectors Vectors whose lines of action meet at one point
Resultant A vector that represents the sum of two or more vectors
Absolute Pressure Atmospheric pressure + gauge pressure
Static Friction A friction force that acts on objects that are not moving. Always greater than kinetic
friction
Kinetic Friction Friction that opposes motion once the motion has already started. Not affected by
speed of body Always greater than rolling friction.
Rolling Friction The friction force that acts on rolling objects, Always less than kinetic friction
Fluid Friction Friction that occurs as an object moves through a fluid
Force of Friction 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 The ability of a material to return to its original shape after being disturbed
