hw 2,3,5 Flashcards
Energy can be changed into another form but cannot be created or destroyed.
True’.
Internal combustion engines convert chemical energy into thermal energy and thermal energy into mechanical energy.
True’.
Pressure and temperature are inversely proportional to each other.
False’.
A typical pressure gauge will read atmospheric pressure as zero.
‘True’.
Vacuum is best defined as any pressure greater than atmospheric pressure.
False’.
It takes two complete camshaft revolutions and one revolution of the crankshaft to complete one engine cycle, firing all cylinders once.
‘False’.
The American Petroleum Institute is a technical society that has established a classification system that standardizes oil viscosity ratings.
False’
A weak valve spring will cause a steady low reading on a vacuum gauge.
False’.
The combustion chamber is the space between the top of the piston and the cylinder head.
True’.
Oils with a higher viscosity rating should be used in colder temperatures.
False
Atmospheric pressure changes with changes in elevation.
True’.
A turbocharged engine is called a normally aspirated engine.
False
Twenty inches of vacuum would be equivalent to how much pressure absolute?
5 psia
The principle that describes using a restriction to increase the speed of a liquid or a gas is called
Venturi principle
Technician A says atmospheric pressure increases as altitude increases. Technician B says atmospheric pressure decreases as altitude increases. Who is correct?
Technician B only
Barometric pressure of 14.7 psi is equivalent to a.
1 bar
b.
1 atmosphere
c.
100 kpa
d.
All of the above
All of the above
If the pressure is increased on a gas in an enclosed container, the temperature of the gas will
Increase
The measurement of the rate at which work is performed is measured in:
Horsepower
For work to have taken place, a mass can be
Lifted/Moved
Vacuum is formed on the
Intake stroke
A low steady reading on a vacuum gauge connected to the intake manifold of an operating engine may be caused by;
Retarded ignition timing/Incorrect valve timing
A cylinder leakage test is used to determine which of the following
The source of leakage from the cylinder/Measure the percentage of compression lost
Technician A says low compression pressures could prevent combustion from occurring inside a cylinder. Technician B says compression pressure is not a factor for complete combustion. Who is correct?
Technician A only
The best place to find the emission and tune-up data about a specific vehicle is the;
Under hood decal
Black smoke from the exhaust is caused by
A rich air/fuel ratio
The purpose of the PCV system is to: a.
Control emissions
b.
Relieve the engine’s crankcase of pressure and vapors
c.
Reduce the formation of oil sludge
All of the above
The period of time that the exhaust and intake valves are both open is called valve:
Overlap
The component that permits fast warm-up of the engine after it has been started is the:
Thermostat
Intake manifold vacuum is the highest during
Deceleration
The best way to check the efficiency of individual cylinders is a:
Power balance test
Approximately how much of an engine’s energy is used to drive the vehicle?
15%
Technician A says an engine with an intake manifold vacuum leak may misfire at idle and lower engine speeds. Technician B says a faster-than-normal idle speed in a fuel-injected engine may be caused by an intake manifold vacuum leak. Who is correct?
Both A and B
Technician A says the exhaust gas from the cylinders of a turbocharged engine is directed past the turbine wheel. Technician B says the exhaust gas from the cylinders of a turbocharged engine is directed past the compressor wheel. Who is correct?
Technician A only
A partially restricted or blocked exhaust system may result in
A rough ldle/Loss of engine power
The supercharger is driven by:
The crankshaft
A turbocharger may be damaged by: a.
Lack of oil
b.
Contaminants in the oil
c.
Ingestion of foreign material through the air intake
All of the above
The three major automotive pollutants are:
HC, CO, and NOx
Oil is found in the air filter housing. What is the most likely cause?
Worn piston rings/Clogged PCV valve
Which of the following can be used to locate both exhaust and vacuum leaks?
Smoke, Electronic leak detector
Which component is responsible for creating engine vacuum?
All of the above
