Stationary Engineering Principles

Question 1

Explain the definition of boiler.

Answer 1

A boiler is a closed vessel containing water. The water in a boiler is pressurized and turned into steam when heat is added.

Question 2

How is water in a boiler converted into steam.

Answer 2

When fuel is burned in the furnace, the chemical energy in the fuel is transformed into heat. The heat, which is form of energy, is released in the steam.

Question 3

Define force and it’s unit of measurement.

Answer 3

Force is a pushing or pulling motion and is commonly measured in pounds.

Question 4

Define Area and what it’s unit of measurement

Answer 4

Area is a surface measured square feet or inches and is usually the amount of surface affected by the force.

Question 5

Equation for area of a rectangle

Answer 5

Area = Length x Width

Question 6

Define Pressure and it’s unit of measurement.

Answer 6

Pressure is force acting on a unit of area.

Pressure is measured in PSI or PSF

Question 7

What two factors determine pressure.

Answer 7

Area and force are used to determine pressure.

Question 8

Write formulas for Pressure, Force, Area

Answer 8

P = F/A F = P x A A = F/P

Question 9

What was used as the primary source of power before machines were invented?

Answer 9

Horses were used as a primary source of power for work. It was determined that a horse could move 33,000 lb a distance of 1 foot in 1 minute.

Question 10

Define energy.

Answer 10

Energy is the ability to do work.

Question 11

Define Potential energy.

Answer 11

Potential energy is energy associated with position and shape.

Question 12

Gives examples of potential energy.

Answer 12

Examples of potential energy are a weight held above a floor or a slingshot in a firing position.

Question 13

Define kinetic energy,

Answer 13

Kinetic energy is energy associated with motion. For example, a moving train is an example of kinetic energy.

Question 14

Define heat.

Answer 14

Heat is energy caused by molecules in motion within a substance.

Question 15

Define latent heat (hidden heat).

Answer 15

Latent heat is heat added to a substance that changes its state without a change of temperature. For example, when water starts to boil, as more heat is added the water turns to steam with no change in temperature.

Question 16

Define latent heat of fusion.

Answer 16

Latent heat of fusion is heat required to change the state of 1 lb of a substance from a solid to a liquid at a constant temperature.

Question 17

How many btu/lb are required to raise 1 lb of ice to 1 lb of water at 32 deg. F.

Answer 17

144 but/lb

Question 18

Define latent heat of evaporation.

Answer 18

The heat necessary to change 1 lb of substance from a liquid to a gas at a constant temperature.

Question 19

Define specific heat.

Answer 19

The amount of heat required to raise the temperature of 1 lb of substance 1 deg. Fahrenheit. For example, the specific heat of ice is 0.5 btu. For every 0.5 but added per pound of ice, the temperature is raised 1 deg. F.

Question 20

Define temperature.

Answer 20

Temperature is the degree or intensity of heat. The quantity of heat is the amount of heat measured in Btu from a given base.

Question 21

Define Conduction.

Answer 21

Conduction is heat transfer that occurs when molecules come in direct contact with each other, and energy is passed from on to the other.

Question 22

Give a example of conduction heat transfer.

Answer 22

If one end of a metal rod is heated, heat is transferred by conduction to the other end.

Question 23

Define Convection.

Answer 23

Convection is heat transfer that occurs when heat is transferred by currents fluid.

Question 24

Give a example of convection heat transfer.

Answer 24

When heat is applied to the bottom of a pot of boiling water the warm water rises and is replaced by cold water.

Question 25

Define Radiation.

Answer 25

Radiation is heat transfer that occurs when heat is transferred without a material carrier.

Question 26

Give example of Radiation.

Answer 26

Light waves reaching the earth from the sun or when a furnace door is opened, the radiant heat of the fire is sensed immediately.

Question 27

What is mechanical energy measured in?

Answer 27

Mechanical energy is measured in Ft-lb.

Question 28

State Charles first law.

Answer 28

Charles first law states that for a constant pressure process, gas volume increases as temp. increases and vice versa.

Question 29

State Charles second law.

Answer 29

For a constant volume process, pressure increase as temperatures increases and vice versa. Temp in ˚R and for press psia.

Question 30

State Boyle’s law

Answer 30

Constant temperature process for each change of pressure, there is an inverse (opposite) change of volume. When pressure increases, volume.