Mechanics Flashcards
A worker in a shop lifts his protective eyewear to inspect his work. A metal fragment from a nearby work station flies onto his eye causing injury. What is the chance that the fragment would strike his eye?
Accident
What is a common example of an accident associated with power, structural, and technical systems?
Falling objects
In an agricultural shop, which is the appropriate color to use for informational signs such as “out of order” or “do not operate?”
yellow
What is the highest priority regarding work done in agricultural power, structural, and technical systems?
safety
what is an example of a hazard?
spill
which is the first step to take in the event of a spill in an agricultural shop?
tell teacher
why is it important for business owners to promote safety in the workplace?
safety regulations
what is the primary system of internal combustion engines commonly known as?
compression system
why must internal combustion engines have a method for achieving ignition in their cylinders?
to start the combustion
what are the components of the operating system?
air intake, fuel, exhaust, lubrication, and starting systems
list the accessory systems of an engine.
power steering, air intake system, and cooling system
what is the overall goal in the compression system?
effectively compress air to increase potential energy resulting from combustion of the fuel
what is the downward movement of the piston?
intake stroke
why should piston rings keep a secure and solid fitting on the top of the piston?
no air could leave or fluids
what is a device that closes the valve and holds it open at the appropriate times?
spring retevers
what devices opens and closes the valves in an engine?
valve springs
what is a component of both the air intake system and fuel system?
Carburetor
what system plays a major role in heat transfer?
cooling system
_____ is part of the liquid cooling system that functions by transferring heat and is a cooling and storage area for the liquid combination of water and antifreeze
radiator
what is the most common problem when working with engines?
lack of knowledge
what should be used to protect against falling objects?
hard hat
the piston operates inside a ____
cylinder block
what is a device that allows the fuel mixture to enter?
intake valves
what is a function of engine oil?
reduce wear on moving parts lubrication
what is the first step in disassembling an engine?
drain all the fluids
during reassemble of an engine, what should be installed in the crankcase?
shaft to keep crankshaft from moving
if a machine is going to be stored for a long period of time then which of the following practices should be performed?
winterized
what is the biggest difference between hand tools and power tools
power tools use electricity
which tool would be the best selection for the prose of cutoff work, including squaring boards, cutting them to length, and cutting them at angles of bevels?
saw
what is a tool that uses a motor to turn either a metal blade with teeth or an abrasive disk to cut through materials?
circular saw
which plumbing system brings fresh water into a structure from a city water main or private well?
fresh, main water line
why should plumbing fixtures be near each other?
increase efficiency and reduce cost
faucets, toilets, showers, washing machines, and water heaters can be classified a _____.
fixtures
what should be consulted before any plumbing work is performed?
local plumbing codes
what devices is designed to stop water flow if needed?
shutoff vavlve
if a home owner needed to measure how much water is being used, then what device would be used?
water meter
where is the hot water supply line routed before it arrives to fixtures?
on the left
how can pressure loss occur within water supply lines?
A leak, size of piping, height of buildings, length of piping
if a home is using a private well for its water source then what maintains the pressure within the system?
water pump
hot water lines should be placed on the ____, and cold water lines should be placed on the ____ when diagramming and installing supply lines
left, right
what is a loud noise in a supply line caused by a volume of water that suddenly stops moving?
water hammer
what can be added to a supply line to provide a cushion of air to absorb the water hammer effect?
air chamber
what is the curved section of a pipe near each fixture that holds water to prevent sewage gases from entering the structure?
traps
What is something worn to minimize risks on the job?
PPE (personal protective equipment)
when lifting heavy object what should a person do?
lift with their legs
what is the most common plumbing problems?
dripping faucets, leaking pipes, and running toilets
what is the smallest units of an element?
atoms
as electrons move around the nucleus, how can this area be described?
rings/shells- valence rings
what is the flow of electrons from atom to atom in a conductor?
electricity
where does the flow of electrons take place?
outer valence ring
what do copper, aluminum, silver, and gold have in common?
good conducters
what is a good semiconductor
silicone
what theories is the accepted model of electrical current flow?
electron theory
one cycle of electricity per second is referred to as ____.
hertz
____ are materials that contain electrons that do not share or move freely.
insulators
what are elementary particles with no electrical charge?
neutrons
___ is the pressure in a circuit that causes the electrons to flow through a conductor.
voltage
what is the amount of electrical current flowing past a point in a circuit?
amperage
which of the following is an instrument used to measure amperage in a circuit?
ammeter
what is a property of any material that opposes the flow of electricity?
resistance
what has a low resistance?
conductors
there are 20 amps of current low in a circuit with a total resistance of 8 ohms then what would be the voltage source?
160 volts
what is the movement of a force through a distance?
work
how much does one kilowatt equal?
1,000 watts
how is electricity sold?
Kilowatt - hour
if .96 amps of current flows through a 120-volt circuit, how many watts of electrical power are being used?
115.2 watts
why is copper preferred over aluminum when wiring most branch circuits?
better conducter
what is used to regulate heating and cooling systems?
thermostats
which of the following are devices used when a convenience outlet is in the same device box with a switch?
breaker box
what is used to trace circuits and to test fuses and lines?
circuit breaker
a ____ is one wire connected to another wire
spliced
if cutting wire, sptripping conductors and attaching to terminals are required then what tool should be used?
wire strippers
how does the electrode holder protect the welder?
so we don’t make electrical contact
what causes the electric energy to be transformed into heat?
kinetic energy
if electrons flow in one direction then what is this situation referred to as?
DC or Direct Current
when the electrons flow from the electrode to the workpiece, it is____.
Arc welding
what do the first two digits of a four-digit number on an electrode indicate?
tensile strength
