DC BOILER EXAM PREP 2023 (FORMULAS
AND CONSTANTS USED FOR THE DC 3RD
CLASS BOILER EXAM) QUESTIONS AND
ANSWERS.
Area of a rectangle - correct answer
Length x Width
Area of a Circle - correct answer
.7854 x Diameter²
Volume of a Box - correct answer
Length x Width x Height
Volume of a Cylinder - correct answer
.7854 x Diameter² x Length
Circumference of a Circle - correct answer
π x Diameter
Unit of Force - correct answer
Pound (lb)
Formula for Force - correct answer
Pressure ÷ Area
,Unit of Work - correct answer
in-lb or ft-lb
Formula for Work - correct answer
Force x Distance
Unit of Power - correct answer
ft-lb/min
Formula for Power - correct answer
= Work ÷ Time
or (Force x Distance) ÷ Time
Formula for Mechanical Horsepower - correct answer
= Power ÷ 33,000 ft-lb/min
Fahrenheit to Celsius - correct answer
°C = (°F - 32) ÷ 1.8
Celsius to Fahrenheit - correct answer
°F = (1.8 x °C) - 32
Fahrenheit to Rankine - correct answer
°R = °F + 460
Celsius to Kelvin - correct answer
,K = °C +273.15
Charles' First Law - correct answer
Volume1 / Pressure1 = Volume2 / Pressure2
Charles' Second Law - correct answer
Pressure1 / Temperature1 = Pressure2 / Temperature2
Boyle's Law - correct answer
Pressure1 x Volume1 = Pressure2 x Volume2
General Gas Law - correct answer
(Pres1 x Vol1)/ Temp1 = (Pres2 x Vol2)/Temp2
Formula for Levers - correct answer
Resistance x DistanceR = Effort x DistanceE
Formula for Inclined Planes - correct answer
Force x Length = Resistance x Height
Formula for Wheel & Axel - correct answer
Force x DistanceF = Resistance x DistanceR
Torque - correct answer
Force x Radius
, Safe Working Pressure of a Riveted Boiler (SWP) - correct
answer
(Area of Staybolt x Stress Constant of Staybolt) ÷ Area Covered
by Staybolt or = (a x C) ÷ A
Area Covered by Staybolt - correct answer
= Pitch x Pitch
Longitudinal Stress - correct answer
(P x D x L) / 2t
P = Pressure
D = Diameter
L = Length
t = thickness of steel
Boiler Heating Surface (tubes) = - correct answer
=CxLx#
C = Circumference of tubes
L = Length of tubes
# = Number of tubes
HS = π x Diameter x Length x Number of Tubes
Watts per Boiler Horsepower - correct answer
746 Watts
Horsepower formula - correct answer
= ft-lb/min ÷ 33000 ft-lb/min
ft-lb formula for a pump - correct answer
AND CONSTANTS USED FOR THE DC 3RD
CLASS BOILER EXAM) QUESTIONS AND
ANSWERS.
Area of a rectangle - correct answer
Length x Width
Area of a Circle - correct answer
.7854 x Diameter²
Volume of a Box - correct answer
Length x Width x Height
Volume of a Cylinder - correct answer
.7854 x Diameter² x Length
Circumference of a Circle - correct answer
π x Diameter
Unit of Force - correct answer
Pound (lb)
Formula for Force - correct answer
Pressure ÷ Area
,Unit of Work - correct answer
in-lb or ft-lb
Formula for Work - correct answer
Force x Distance
Unit of Power - correct answer
ft-lb/min
Formula for Power - correct answer
= Work ÷ Time
or (Force x Distance) ÷ Time
Formula for Mechanical Horsepower - correct answer
= Power ÷ 33,000 ft-lb/min
Fahrenheit to Celsius - correct answer
°C = (°F - 32) ÷ 1.8
Celsius to Fahrenheit - correct answer
°F = (1.8 x °C) - 32
Fahrenheit to Rankine - correct answer
°R = °F + 460
Celsius to Kelvin - correct answer
,K = °C +273.15
Charles' First Law - correct answer
Volume1 / Pressure1 = Volume2 / Pressure2
Charles' Second Law - correct answer
Pressure1 / Temperature1 = Pressure2 / Temperature2
Boyle's Law - correct answer
Pressure1 x Volume1 = Pressure2 x Volume2
General Gas Law - correct answer
(Pres1 x Vol1)/ Temp1 = (Pres2 x Vol2)/Temp2
Formula for Levers - correct answer
Resistance x DistanceR = Effort x DistanceE
Formula for Inclined Planes - correct answer
Force x Length = Resistance x Height
Formula for Wheel & Axel - correct answer
Force x DistanceF = Resistance x DistanceR
Torque - correct answer
Force x Radius
, Safe Working Pressure of a Riveted Boiler (SWP) - correct
answer
(Area of Staybolt x Stress Constant of Staybolt) ÷ Area Covered
by Staybolt or = (a x C) ÷ A
Area Covered by Staybolt - correct answer
= Pitch x Pitch
Longitudinal Stress - correct answer
(P x D x L) / 2t
P = Pressure
D = Diameter
L = Length
t = thickness of steel
Boiler Heating Surface (tubes) = - correct answer
=CxLx#
C = Circumference of tubes
L = Length of tubes
# = Number of tubes
HS = π x Diameter x Length x Number of Tubes
Watts per Boiler Horsepower - correct answer
746 Watts
Horsepower formula - correct answer
= ft-lb/min ÷ 33000 ft-lb/min
ft-lb formula for a pump - correct answer
