Steam Engines Trivia Quiz Questions and Answers

Imagine you’re working in a bustling factory in 1910. What is the primary source of power for your machines?

• Electricity
• Solar Energy
• Steam Engines
• Windmills

Correct Answer: Steam Engines

Correct Answer Explanation: In the early 20th century, steam engines were the dominant power source for industry and transportation.

What is the main principle behind the operation of a steam engine?

• Utilizing the force of gravity
• Converting heat into mechanical work
• Harnessing the power of the wind
• Generating electricity from water

Correct Answer: Converting heat into mechanical work

Correct Answer Explanation: Steam engines convert heat energy from burning fuel into mechanical work, utilizing the expansion of steam.

Think about the basic parts of a steam engine. Which of these is NOT a key component?

• Piston
• Cylinder
• Connecting Rod
• Gearbox

Correct Answer: Gearbox

Correct Answer Explanation: While gearboxes are important for transmitting power in many machines, they are not a fundamental component of a steam engine.

Inside a steam engine, what is the purpose of the slide valve?

• To regulate the flow of steam
• To control the engine’s speed
• To lubricate the piston
• To ignite the fuel

Correct Answer: To regulate the flow of steam

Correct Answer Explanation: The slide valve opens and closes ports in the cylinder, allowing steam to enter and exit, driving the piston.

Why is an eccentric a vital part of a steam engine?

• It helps reduce friction in the cylinder
• It acts as a safety valve
• It drives the slide valve’s movement
• It controls the fuel supply

Correct Answer: It drives the slide valve’s movement

Correct Answer Explanation: The eccentric, a rotating crank, provides the back-and-forth motion necessary to operate the slide valve.

What is the “cut-off” point in a steam engine’s cycle?

• The point where steam is released from the cylinder
• The point where the piston reaches its furthest point
• The point where steam admission is stopped, allowing expansion
• The point where the engine changes direction

Correct Answer: The point where steam admission is stopped, allowing expansion

Correct Answer Explanation: The cut-off point is crucial for controlling the expansion ratio of steam, impacting efficiency.

What is the main factor that determines the efficiency of a steam engine?

• The size of the engine
• The type of fuel used
• The amount of steam pressure
• The amount of steam expansion and condensation

Correct Answer: The amount of steam expansion and condensation

Correct Answer Explanation: Cylinder condensation, where steam loses heat to the cooler cylinder walls, reduces efficiency. Multiple expansion engines help minimize this by expanding steam in stages.

Imagine a steam engine exhausts into a condenser. What is the primary benefit of this design?

• It reduces noise pollution
• It allows for faster engine speeds
• It increases power output and potentially improves efficiency
• It makes the engine more compact

Correct Answer: It increases power output and potentially improves efficiency

Correct Answer Explanation: Condensing steam lowers back pressure, allowing the piston to move with less resistance, increasing power and potentially reducing steam consumption.

What are “indicators” used for in steam engine testing?

• To measure the engine’s speed
• To determine the type of fuel used
• To create diagrams showing pressure changes in the cylinder
• To control the engine’s steam pressure

Correct Answer: To create diagrams showing pressure changes in the cylinder

Correct Answer Explanation: Indicators provide visual representations of pressure variations in the cylinder during each stroke, providing valuable information on performance.

What tool is used to measure the area of an indicator diagram, crucial for calculating power output?

• A planimeter
• A micrometer
• A thermometer
• A barometer

Correct Answer: A planimeter

Correct Answer Explanation: A planimeter is a specialized instrument that measures the area of an indicator diagram, helping to determine the mean effective pressure and calculate the engine’s horsepower.

How is the steam consumption of an engine typically measured?

• In pounds of steam per horsepower per hour
• In gallons of water per minute
• In cubic feet of steam per second
• In revolutions per minute

Correct Answer: In pounds of steam per horsepower per hour

Correct Answer Explanation: This “water rate” reflects how efficiently the engine converts steam into work, a key indicator of its performance.

What is the “mechanical efficiency” of a steam engine?

• The ratio of indicated horsepower to brake horsepower
• The ratio of brake horsepower to indicated horsepower
• The percentage of fuel converted to steam
• The amount of heat lost through condensation

Correct Answer: The ratio of brake horsepower to indicated horsepower

Correct Answer Explanation: It indicates how much of the engine’s power is lost to friction and other mechanical inefficiencies.

Why do steam engines typically perform best at their designed full load?

• Because they are most efficient at full load
• Because they can operate at higher speeds
• Because they require less maintenance
• Because they consume less fuel

Correct Answer: Because they are most efficient at full load

Correct Answer Explanation: Operating at full load allows the engine to utilize its designed capacity and minimizes losses due to throttling or other inefficiencies.

What is the term for the ratio of the final volume of steam to its initial volume at the cut-off point?

• Compression ratio
• Expansion ratio
• Release ratio
• Clearance ratio

Correct Answer: Expansion ratio

Correct Answer Explanation: The expansion ratio is a significant factor in determining the efficiency of a steam engine.

What is “clearance” in a steam engine?

• The space between the piston and the cylinder head at the end of a stroke
• The length of the connecting rod
• The size of the steam ports
• The amount of steam pressure

Correct Answer: The space between the piston and the cylinder head at the end of a stroke

Correct Answer Explanation: Clearance affects the volume of steam that must be heated and expanded each cycle, impacting efficiency.

What is “back pressure” in a steam engine?

• The pressure in the cylinder during exhaust
• The steam pressure in the boiler
• The force acting on the piston
• The speed of the engine

Correct Answer: The pressure in the cylinder during exhaust

Correct Answer Explanation: Back pressure opposes the piston’s movement during exhaust, reducing the engine’s efficiency. Condensing engines significantly lower back pressure.

What does “mean effective pressure” (M.E.P.) represent in a steam engine?

• The average pressure acting on the piston during a stroke
• The maximum pressure in the cylinder
• The pressure at the cut-off point
• The pressure during exhaust

Correct Answer: The average pressure acting on the piston during a stroke

Correct Answer Explanation: M.E.P. is crucial for calculating the engine’s power output.

What is the unit of measurement for work?

• Joules
• Horsepower
• Foot-pounds
• Watts

Correct Answer: Foot-pounds

Correct Answer Explanation: Foot-pounds represent the force exerted to raise a weight of 1 pound a distance of 1 foot, a fundamental unit for measuring work.

What is the term for the process of compressing steam in the cylinder at the end of the exhaust stroke?

• Release
• Expansion
• Compression
• Cut-off

Correct Answer: Compression

Correct Answer Explanation: Compression helps to cushion the piston’s movement and prepare for the next intake of steam, improving efficiency.

Why is a large clearance considered undesirable in steam engine design?

• It reduces the engine’s speed
• It increases friction
• It requires more steam to fill the cylinder at the start of each stroke
• It increases the risk of explosions

Correct Answer: It requires more steam to fill the cylinder at the start of each stroke

Correct Answer Explanation: A large clearance volume means more steam must be heated and expanded, leading to increased steam consumption and reduced efficiency.

What is the theoretical back pressure in a non-condensing engine?

• 0 pounds per square inch
• 14.7 pounds per square inch above a vacuum
• 21 pounds per square inch
• 30 pounds per square inch

Correct Answer: 14.7 pounds per square inch above a vacuum

Correct Answer Explanation: This represents the pressure against which the piston must work in a non-condensing engine, as the steam is simply released to the atmosphere.

What is the typical back pressure in a condensing engine?

• 17 pounds per square inch
• 3 pounds per square inch
• 10 pounds per square inch
• 25 pounds per square inch

Correct Answer: 3 pounds per square inch

Correct Answer Explanation: Condensing engines significantly reduce back pressure by exhausting steam into a condenser, leading to greater efficiency.

What is the typical range for the brake horsepower of a steam engine compared to its indicated horsepower?

• 50-60%
• 80-90%
• 110-120%
• 150-160%

Correct Answer: 80-90%

Correct Answer Explanation: This reflects the typical power loss due to friction and other mechanical inefficiencies in steam engines.

What is the average water rate for different types of steam engines working at full load?

• 10-15 pounds of steam per horsepower per hour
• 24-33 pounds of steam per horsepower per hour
• 40-50 pounds of steam per horsepower per hour
• 60-70 pounds of steam per horsepower per hour

Correct Answer: 24-33 pounds of steam per horsepower per hour

Correct Answer Explanation: This range shows the variability in steam consumption for different engine designs and operating conditions.

What is the most economical ratio of expansion for simple steam engines?

• 2-3
• 4-5
• 6-7
• 8-9

Correct Answer: 4-5

Correct Answer Explanation: Higher expansion ratios can lead to increased condensation losses, limiting the practicality of exceeding this range in simple engines.

What is the typical ratio of expansion for compound engines?

• 2-4
• 5-7
• 8-10
• 12-14

Correct Answer: 8-10

Correct Answer Explanation: Compound engines, by expanding steam in multiple stages, can achieve higher expansion ratios while minimizing condensation losses.

What is the typical range for the expansion ratio in triple expansion steam engines?

• 5-8
• 10-12
• 12-15
• 18-20

Correct Answer: 12-15

Correct Answer Explanation: Triple expansion engines, utilizing three stages of expansion, can achieve even greater expansion ratios, further boosting efficiency.

What is the theoretical gain in economy from condensing a simple steam engine?

• 5-10%
• 15-20%
• 28-30%
• 40-45%

Correct Answer: 28-30%

Correct Answer Explanation: Condensing steam significantly lowers back pressure, potentially leading to significant reductions in steam consumption.

What is a major factor that affects the actual gain in economy from condensing a steam engine?

• The type of fuel used
• The engine’s speed
• The cost and operation of the condenser
• The ambient temperature

Correct Answer: The cost and operation of the condenser

Correct Answer Explanation: While condensing offers potential savings, the practical considerations of condenser design, operation, and maintenance impact the overall economic benefits.

What is the typical piston speed range for simple high-speed steam engines?

• 200-400 feet per minute
• 400-600 feet per minute
• 600-800 feet per minute
• 800-1000 feet per minute

Correct Answer: 600-800 feet per minute

Correct Answer Explanation: This range provides a reference for understanding the typical operating speed of this type of engine.

What is the typical reduction in efficiency of actual steam engines compared to theoretical performance?

• 5-10%
• 15-20%
• 25-30%
• 35-40%

Correct Answer: 25-30%

Correct Answer Explanation: Real-world engines experience losses due to factors like friction, condensation, and imperfect valve operation, resulting in a reduction in efficiency compared to ideal conditions.

What is the term for the amount of steam consumption calculated from an indicator diagram?

• Steam rate
• Water rate
• Back pressure
• Mean effective pressure

Correct Answer: Water rate

Correct Answer Explanation: This represents the steam consumption per horsepower per hour, a crucial measurement for evaluating engine efficiency.

If the cylinder condensation is 20% of the total steam consumption, what is the effect on the water rate?

• The water rate decreases by 20%
• The water rate increases by 20%
• The water rate remains unchanged
• The water rate is halved

Correct Answer: The water rate increases by 20%

Correct Answer Explanation: Cylinder condensation represents a loss of steam energy, leading to increased overall steam consumption and a higher water rate.

What is the term for the fundamental relationship between heat energy and mechanical work?

• Newton’s Law of Motion
• Bernoulli’s Principle
• First Law of Thermodynamics
• Second Law of Thermodynamics

Correct Answer: First Law of Thermodynamics

Correct Answer Explanation: The First Law of Thermodynamics states that energy cannot be created or destroyed, only transformed from one form to another, a principle that underpins the operation of steam engines.

What is the volume of 1 pound of steam at 20 pounds per square inch?

• 10 cubic feet
• 15 cubic feet
• 20 cubic feet
• 25 cubic feet

Correct Answer: 20 cubic feet

Correct Answer Explanation: This relationship between steam pressure and volume is crucial for understanding steam consumption and engine performance.

Why do high-speed engines require a greater amount of compression than low-speed engines?

• To reduce friction
• To prevent overheating
• To cushion the piston’s movement
• To increase the engine’s power

Correct Answer: To cushion the piston’s movement

Correct Answer Explanation: Compression helps to slow down the piston at the end of the stroke, providing a cushion and reducing wear on the engine components.

What is the typical range for clearance values in steam engines?

• 0.5-2%
• 1.5-10%
• 12-18%
• 20-25%

Correct Answer: 1.5-10%

Correct Answer Explanation: This range shows the variability in clearance based on engine design, speed, and intended application.

What is the primary source of energy loss in a steam engine?

• Friction
• Condensation
• Exhaust
• Radiation

Correct Answer: Condensation

Correct Answer Explanation: While friction plays a role, condensation, where steam loses heat to the cooler cylinder walls, is a significant source of energy loss in steam engines, reducing their efficiency.

Why was steam jacketing used in early steam engine designs?

• To increase engine speed
• To reduce cylinder condensation
• To improve fuel efficiency
• To prevent overheating

Correct Answer: To reduce cylinder condensation

Correct Answer Explanation: Steam jacketing, involving surrounding the cylinder with hot steam, was an early attempt to minimize temperature differences and reduce condensation losses.

What is the primary advantage of using superheated steam in steam engines?

• It reduces cylinder condensation
• It increases engine speed
• It reduces friction
• It increases the power output

Correct Answer: It reduces cylinder condensation

Correct Answer Explanation: Superheated steam, at a higher temperature, can cool slightly before condensation begins, reducing initial condensation losses and improving engine efficiency.

What are the primary instruments used to measure the performance of steam engines?

• Speedometer and tachometer
• Thermometer and barometer
• Indicators and planimeters
• Manometer and flow meter

Correct Answer: Indicators and planimeters

Correct Answer Explanation: Indicators create diagrams showing pressure changes in the cylinder, while planimeters measure the area of these diagrams, providing essential data for evaluating engine performance and efficiency.

What is the term for the mechanical efficiency of an engine, representing the ratio of brake horsepower to indicated horsepower?

• Thermal efficiency
• Mechanical efficiency
• Steam rate
• Expansion ratio

Correct Answer: Mechanical efficiency

Correct Answer Explanation: Mechanical efficiency indicates how much of the engine’s power is lost to friction and other mechanical inefficiencies.

What is the term for the ratio of heat converted to work to total heat supplied, representing how effectively the engine transforms heat energy into mechanical work?

• Mechanical efficiency
• Thermal efficiency
• Steam rate
• Expansion ratio

Correct Answer: Thermal efficiency

Correct Answer Explanation: Thermal efficiency reflects the overall efficiency of the engine in converting heat energy into useful work, a fundamental measure of its performance.

What is the primary benefit of condensing steam in a steam engine?

• It reduces noise pollution
• It increases engine speed
• It reduces steam consumption
• It increases power output

Correct Answer: It increases power output

Correct Answer Explanation: Condensing steam lowers back pressure, allowing the piston to move with less resistance, resulting in greater power output per stroke.

What is the primary reason for the development of compound and triple expansion engines?

• To increase engine speed
• To reduce fuel consumption
• To reduce noise pollution
• To increase power output

Correct Answer: To reduce fuel consumption

Correct Answer Explanation: Compound and triple expansion engines were developed to improve efficiency by minimizing cylinder condensation and allowing for greater expansion ratios, leading to reduced steam consumption.

What was the primary role of steam engines in the early 20th century?

• Generating electricity
• Powering automobiles
• Providing heat for homes
• Driving industrial machinery and transportation

Correct Answer: Driving industrial machinery and transportation

Correct Answer Explanation: Steam engines were the dominant power source for industry and transportation in the early 20th century, driving factories, ships, and trains.

What is the term for the process of using steam to heat the cylinder walls, reducing condensation?

• Superheating
• Jacketing
• Condensing
• Throttling

Correct Answer: Jacketing

Correct Answer Explanation: Steam jacketing was an early attempt to improve steam engine efficiency by minimizing cylinder condensation.

What is the term for the steam pressure in the boiler, the source of power for the engine?

• Back pressure
• Cut-off pressure
• Boiler pressure
• Mean effective pressure

Correct Answer: Boiler pressure

Correct Answer Explanation: Boiler pressure is the driving force behind the operation of a steam engine, providing the energy for steam expansion and piston movement.

What is the primary factor that determines the speed of a steam engine?

• The size of the engine
• The type of fuel used
• The amount of steam pressure
• The governor mechanism

Correct Answer: The governor mechanism

Correct Answer Explanation: Governors regulate the speed of a steam engine by controlling the amount of steam admitted to the cylinder, ensuring stable operation.

What is the term for the point in the stroke where the exhaust valve opens, releasing steam from the cylinder?

• Release
• Compression
• Cut-off
• Expansion

Correct Answer: Release

Correct Answer Explanation: Release marks the end of the power stroke, allowing the spent steam to exit the cylinder.

What is the term for the process of controlling the amount of steam admitted to the cylinder, affecting the engine’s speed and power output?

• Throttling
• Jacketing
• Condensing
• Superheating

Correct Answer: Throttling

Correct Answer Explanation: Throttling involves regulating the steam flow to the cylinder, providing a means to control engine speed and power.

What is the primary advantage of using multiple expansion engines, such as compound and triple expansion engines?

• Increased engine speed
• Reduced fuel consumption
• Reduced noise pollution
• Increased power output

Correct Answer: Reduced fuel consumption

Correct Answer Explanation: Multiple expansion engines improve efficiency by minimizing condensation losses and allowing for greater expansion ratios, leading to reduced steam consumption.

What is the term for the type of steam engine that exhausts steam to the atmosphere rather than to a condenser?

• Condensing engine
• Non-condensing engine
• Compound engine
• Triple expansion engine

Correct Answer: Non-condensing engine

Correct Answer Explanation: Non-condensing engines have a higher back pressure, resulting in reduced efficiency compared to condensing engines.

What is the term for the space between the cylinder head and the piston at the end of the stroke, including the steam port?

• Expansion ratio
• Clearance
• Compression
• Release

Correct Answer: Clearance

Correct Answer Explanation: Clearance volume is a significant factor in steam engine efficiency, as it represents the space that must be filled with steam at each cycle.

What is the term for the process of increasing the temperature of steam beyond its saturation point, reducing condensation losses?

• Condensing
• Jacketing
• Superheating
• Throttling

Correct Answer: Superheating

Correct Answer Explanation: Superheating steam improves efficiency by reducing initial condensation losses, as the steam can cool slightly before condensation begins.

What is the term for the pressure in the cylinder during exhaust, opposing the piston’s motion?

• Boiler pressure
• Cut-off pressure
• Back pressure
• Mean effective pressure

Correct Answer: Back pressure

Correct Answer Explanation: Back pressure represents the resistance against which the piston must work during exhaust, impacting the engine’s efficiency.

What is the term for the average pressure acting on the piston during a stroke, crucial for calculating the engine’s power output?

• Cut-off pressure
• Boiler pressure
• Mean effective pressure
• Back pressure

Correct Answer: Mean effective pressure

Correct Answer Explanation: Mean effective pressure (M.E.P.) represents the average pressure that drives the piston during a cycle, providing a key parameter for evaluating engine performance.

What is the term for the device that creates diagrams showing pressure changes in the cylinder during each stroke?

• Planimeter
• Indicator
• Governor
• Throttle

Correct Answer: Indicator

Correct Answer Explanation: Indicators are essential tools for steam engine testing, providing valuable information about pressure variations and engine performance.

What is the primary purpose of using a planimeter in steam engine testing?

• To measure the engine’s speed
• To measure the area of an indicator diagram
• To control the engine’s steam pressure
• To determine the type of fuel used

Correct Answer: To measure the area of an indicator diagram

Correct Answer Explanation: Planimeters are used to measure the area of indicator diagrams, which is crucial for calculating the mean effective pressure and determining the engine’s power output.

What is the term for the measurement of steam consumption in pounds per horsepower per hour?

• Steam rate
• Water rate
• Expansion ratio
• Mechanical efficiency

Correct Answer: Water rate

Correct Answer Explanation: Water rate is a key indicator of engine efficiency, reflecting how efficiently the engine converts steam into work.

What is the term for the ratio of brake horsepower to indicated horsepower, representing the mechanical efficiency of an engine?

• Thermal efficiency
• Steam rate
• Expansion ratio
• Mechanical efficiency

Correct Answer: Mechanical efficiency

Correct Answer Explanation: Mechanical efficiency reflects the power losses due to friction and other mechanical inefficiencies in the engine.

What is the term for the ratio of heat converted to work to total heat supplied, representing the overall efficiency of the engine in converting heat energy into useful work?

• Mechanical efficiency
• Thermal efficiency
• Steam rate
• Expansion ratio

Correct Answer: Thermal efficiency

Correct Answer Explanation: Thermal efficiency is a fundamental measure of engine performance, indicating how effectively heat energy is transformed into mechanical work.

What is the primary reason for the development of condensing engines?

• To reduce noise pollution
• To increase engine speed
• To reduce steam consumption
• To increase power output

Correct Answer: To increase power output

Correct Answer Explanation: Condensing steam lowers back pressure, allowing the piston to move with less resistance, resulting in greater power output per stroke.

What is the primary advantage of using multiple expansion engines, such as compound and triple expansion engines, over simple engines?

• Increased engine speed
• Reduced fuel consumption
• Reduced noise pollution
• Increased power output

Correct Answer: Reduced fuel consumption

Correct Answer Explanation: Multiple expansion engines improve efficiency by minimizing condensation losses and allowing for greater expansion ratios, leading to reduced steam consumption.

What is the primary role of steam engines in the early 20th century?

• Generating electricity
• Powering automobiles
• Providing heat for homes
• Driving industrial machinery and transportation

Correct Answer: Driving industrial machinery and transportation

Correct Answer Explanation: Steam engines were the dominant power source for industry and transportation in the early 20th century, driving factories, ships, and trains.

What is the term for the process of using steam to heat the cylinder walls, reducing condensation?

• Superheating
• Jacketing
• Condensing
• Throttling

Correct Answer: Jacketing

Correct Answer Explanation: Steam jacketing was an early attempt to improve steam engine efficiency by minimizing cylinder condensation.

What is the term for the steam pressure in the boiler, the source of power for the engine?

• Back pressure
• Cut-off pressure
• Boiler pressure
• Mean effective pressure

Correct Answer: Boiler pressure

Correct Answer Explanation: Boiler pressure is the driving force behind the operation of a steam engine, providing the energy for steam expansion and piston movement.

What is the primary factor that determines the speed of a steam engine?

• The size of the engine
• The type of fuel used
• The amount of steam pressure
• The governor mechanism

Correct Answer: The governor mechanism

Correct Answer Explanation: Governors regulate the speed of a steam engine by controlling the amount of steam admitted to the cylinder, ensuring stable operation.

What is the term for the point in the stroke where the exhaust valve opens, releasing steam from the cylinder?

• Release
• Compression
• Cut-off
• Expansion

Correct Answer: Release

Correct Answer Explanation: Release marks the end of the power stroke, allowing the spent steam to exit the cylinder.

What is the term for the process of controlling the amount of steam admitted to the cylinder, affecting the engine’s speed and power output?

• Throttling
• Jacketing
• Condensing
• Superheating

Correct Answer: Throttling

Correct Answer Explanation: Throttling involves regulating the steam flow to the cylinder, providing a means to control engine speed and power.

What is the primary advantage of using multiple expansion engines, such as compound and triple expansion engines?

• Increased engine speed
• Reduced fuel consumption
• Reduced noise pollution
• Increased power output

Correct Answer: Reduced fuel consumption

Correct Answer Explanation: Multiple expansion engines improve efficiency by minimizing condensation losses and allowing for greater expansion ratios, leading to reduced steam consumption.

What is the term for the type of steam engine that exhausts steam to the atmosphere rather than to a condenser?

• Condensing engine
• Non-condensing engine
• Compound engine
• Triple expansion engine

Correct Answer: Non-condensing engine

Correct Answer Explanation: Non-condensing engines have a higher back pressure, resulting in reduced efficiency compared to condensing engines.

What is the term for the space between the cylinder head and the piston at the end of the stroke, including the steam port?

• Expansion ratio
• Clearance
• Compression
• Release

Correct Answer: Clearance

Correct Answer Explanation: Clearance volume is a significant factor in steam engine efficiency, as it represents the space that must be filled with steam at each cycle.

What is the term for the process of increasing the temperature of steam beyond its saturation point, reducing condensation losses?

• Condensing
• Jacketing
• Superheating
• Throttling

Correct Answer: Superheating

Correct Answer Explanation: Superheating steam improves efficiency by reducing initial condensation losses, as the steam can cool slightly before condensation begins.

What is the term for the pressure in the cylinder during exhaust, opposing the piston’s motion?

• Boiler pressure
• Cut-off pressure
• Back pressure
• Mean effective pressure

Correct Answer: Back pressure

Correct Answer Explanation: Back pressure represents the resistance against which the piston must work during exhaust, impacting the engine’s efficiency.

What is the term for the average pressure acting on the piston during a stroke, crucial for calculating the engine’s power output?

• Cut-off pressure
• Boiler pressure
• Mean effective pressure
• Back pressure

Correct Answer: Mean effective pressure

Correct Answer Explanation: Mean effective pressure (M.E.P.) represents the average pressure that drives the piston during a cycle, providing a key parameter for evaluating engine performance.

What is the term for the device that creates diagrams showing pressure changes in the cylinder during each stroke?

• Planimeter
• Indicator
• Governor
• Throttle

Correct Answer: Indicator

Correct Answer Explanation: Indicators are essential tools for steam engine testing, providing valuable information about pressure variations and engine performance.

What is the primary purpose of using a planimeter in steam engine testing?

• To measure the engine’s speed
• To measure the area of an indicator diagram
• To control the engine’s steam pressure
• To determine the type of fuel used

Correct Answer: To measure the area of an indicator diagram

Correct Answer Explanation: Planimeters are used to measure the area of indicator diagrams, which is crucial for calculating the mean effective pressure and determining the engine’s power output.

What is the term for the measurement of steam consumption in pounds per horsepower per hour?

• Steam rate
• Water rate
• Expansion ratio
• Mechanical efficiency

Correct Answer: Water rate

Correct Answer Explanation: Water rate is a key indicator of engine efficiency, reflecting how efficiently the engine converts steam into work.

What is the term for the ratio of brake horsepower to indicated horsepower, representing the mechanical efficiency of an engine?

• Thermal efficiency
• Steam rate
• Expansion ratio
• Mechanical efficiency

Correct Answer: Mechanical efficiency

Correct Answer Explanation: Mechanical efficiency reflects the power losses due to friction and other mechanical inefficiencies in the engine.

What is the term for the ratio of heat converted to work to total heat supplied, representing the overall efficiency of the engine in converting heat energy into useful work?

• Mechanical efficiency
• Thermal efficiency
• Steam rate
• Expansion ratio

Correct Answer: Thermal efficiency

Correct Answer Explanation: Thermal efficiency is a fundamental measure of engine performance, indicating how effectively heat energy is transformed into mechanical work.

What is the primary reason for the development of condensing engines?

• To reduce noise pollution
• To increase engine speed
• To reduce steam consumption
• To increase power output

Correct Answer: To increase power output

Correct Answer Explanation: Condensing steam lowers back pressure, allowing the piston to move with less resistance, resulting in greater power output per stroke.

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