Power engineering Class 4 Part B Exam Questions With Complete Solutions

Power engineering
Class 4 Part B
Exam Questions
With Complete
Solutions


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