4th Class Power Engineering Part A Exam Questions Complete With Correct Answers

4th Class Power Engineering Part A Exam Questions Complete With Correct Answers Q.Velocity (m/s) - ANSWERS-Change in position / time Q.Acceleration (m/s^2) - ANSWERS-Change in velocity (m/s) / time (s) Q.Force (Newton) - ANSWERS-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 Q.Force of Gravity - ANSWERS-mass (kg) x 9.81 m/s^2 Q.Pressure (Pa) - ANSWERS-Force (N) / area (m^2) Q.Work (J) - ANSWERS-Force (N) x distance (m) Q.Power - ANSWERS-Work done / time , Rate of doing work Q.Potential Energy (J) - ANSWERS-mass x gravity x height , the ability of a body to do work due by virtue of its position Q.Kinetic Energy (J) - ANSWERS-1/2 x mass x velocity^2 , The ability of a body to do work due to its motion Q.Energy (J) - ANSWERS-The capacity of a body to do work Q.Tonne - ANSWERS-1000 kilograms Q.Moment of Force (Nm) - ANSWERS-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 Q.Clockwise Moments - ANSWERS-Equal to Counter-clockwise moments Q.Upward Forces - ANSWERS-Equal to Downward forces Q.Actual Mechanical Advantage (Ma) - ANSWERS-Load (N) / Effort (N) Q.Velocity Ratio (VR) - ANSWERS-Distance moved by Effort / Distance moved by Load Q.Efficiency - ANSWERS-Output Work / Input Work Q.Output Work - ANSWERS-Load x Distance moved by load Q.Input Work - ANSWERS-Effort x Distance moved by effort , Equals Output work + Wasted work Q.Ideal Mechanical Advantage (MA) - ANSWERS-Equal to Velocity Ratio (VR) Q.Load x r - ANSWERS-Equal to Effort x R Q.VR - ANSWERS-Equal to R/r and D/d Q.Load /Effort - ANSWERS-Equal to R/r Q.Scalar - ANSWERS-A physical quantity that has magnitude but no direction Q.Vector - ANSWERS-A quantity that has magnitude and direction Q.Space Diagram - ANSWERS-Illustrates a system of vectors Q.Co-planar Vectors - ANSWERS-Vectors that are all in the same plane Q.Concurrent Vectors - ANSWERS-Vectors whose lines of action meet at one point Q.Resultant - ANSWERS-A vector that represents the sum of two or more vectors Q.Absolute Pressure - ANSWERS-Atmospheric pressure + gauge pressure Q.Static Friction - ANSWERS-A friction force that acts on objects that are not moving. Always greater than kinetic friction Q.Kinetic Friction - ANSWERS-Friction that opposes motion once the motion has already started. Not affected by speed of body Always greater than rolling friction. Q.Rolling Friction - ANSWERS-The friction force that acts on rolling objects, Always less than kinetic friction Q.Fluid Friction - ANSWERS-Friction that occurs as an object moves through a fluid Q.Force of Friction - ANSWERS-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. Q.Elasticity - ANSWERS-The ability of a material to return to its original shape after being disturbed Q.Stiffness - ANSWERS-Ability of a material to resist a change in shape or size when a load is applied Q.Plasticity - ANSWERS-Ability of a material to retain its deformed shape when a deforming force is removed Q.Ductility - ANSWERS-Ability of a material to be stretched and reduced in cross section without breaking Q.Toughness - ANSWERS-Ability of a material to absorb energy before breaking Q.Hardness - ANSWERS-Ability of a material to resist penetration Q.Stress - ANSWERS-Internal resistance to an external load , Equal to Load (N) / Area (m^2) Q.Tensile Stress - ANSWERS-Forces that act at opposite ends of a bar and pull away from each other, creating tension on the bar Q.Compressive Stress - ANSWERS-A stress due to a force pushing together on a body Q.Shear Stress - ANSWERS-Forces on a bar that act parallel to another but are not on the same plane Q.Ultimate Stress - ANSWERS-The stress at which fracture of the material occurs Q.Allowable Stress - ANSWERS-The greatest stress which a material is capable of developing without permanent deformation remaining upon the complete release of stress. Q.Elastic Limit - ANSWERS-Maximum stress that a material will withstand without permanent deformation. Will return to its original size and shape Q.Factor of Safety - ANSWERS-Ultimate Stress / Allowable Stress Q.Strain - ANSWERS-A measure of the deformation produced in a member by a load , Equal to Change in Length (l) / Original Length (L) Q.Circumferance - ANSWERS-pi x Diameter Q.Linear Speed - ANSWERS-Equal to rev/min x pi D / 60 Q.Four States of Matter - ANSWERS-solid, liquid, gas, plasma