Exam 4 Flashcards
When refrigerant passes through the condenser, the refrigerant liquid will still be warm or hot to the touch and will still be under a high pressure of ___ to ___ psi.
100 to 250 psi
Even when the thermostat is ____ open, it ____ down the flow of coolant.
Wide
Slows
Manufacturers recommend draining, flushing and replacing the coolant every __ months or __ 000 km.
12 months
48 000 km
During charge, another chemical reaction is taking place. _______ on the positive and negative plates is forced back into the electrolyte where it is able to combine with hydrogen and reform acid.
Sulphate
________ refers to a liquid changing into a vapour state. Heat is absorbed when a liquid changes into a _____.
Vaporization
Vapour
Fan blades with flexible trailing edges are also called a ______ pitch fan, flexible or ___ fan.
Variable
Flex
When a diode is incorporated into a circuit, it allows current to flow in one _______, but blocks current flow in the _______ direction.
Direction
Opposite
_________ refers to a vapour changing into a liquid state. Heat is _____ off when a vapour changes into a liquid.
Condensation
given
The battery case is made of impact-resistant ______ to withstand acid and thermal shock.
Plastic
Hoses are typically made from _____ or ______ rubber and must be able to withstand extreme heat as well as extreme cold.
Butyl
Neoprene
______ wiring is the low-voltage wiring in the automobile wiring system. This includes all lighting, accessories and power distribution circuits.
Primary
Antifreeze products are typically manufactured from ________ products and are considered toxic.
Petroleum
Protection is arranged in several levels. The first protection is as close to the _____ as possible and has a fairly high current rating.
Battery
The pressure relief _____ controls the maximum pressure in the system.
Spring
After installation of any radiator, always make sure the ______ or _____ valve is closed to prevent accidental spills when filling.
Petcock
Drain Valve
Most radiators in today’s vehicles are of the _____-____ design.
Cross-Flow
The thermostat should open within _°C to _°C of the rating stamped on it.
3 to 6
When the engine is ____, the thermostat is _____ and forces the coolant to bypass the radiator and only circulate through the engine.
Cold
Closed
When recharging adjust the gauge suction valve so that the gauge pressure does not exceed __ psi.
50 psi
If the system is low on refrigerant, ______ will show up in the sight glass.
Bubbles
The discharge of static electricity is called _________ discharge (ESD)
Electrostatic
Too little AC oil can result in compressor _____, and too much can result in insufficient _____.
Seizure
Cooling
The _______ battery cable must always be disconnected first and should reconnected last.
Negative
A ________ short may occur when two power wires lose their insulation. If the live bare wires come in contact with each other, more than one component may operate when the switch is turned on.
Crossover
All AC system components are connected with ____.
Lines
R-12 has a boiling point of __ºF (-6°C)
22 F
________ belts are very common on today’s models and usually only one is used to drive all the belt-driven accessories.
Serpentine
A _________ is a substance with a low boiling point.
Refrigerant
_____ belts have been common on automobiles for more than 60 years.
Drive belts
____ fans are used to improve fuel economy.
Flex
Strip the insulation from the wire, leaving ____ an inch of copper showing.
Half and inch
Water by itself causes _____ and ____ to build up in the cooling passages, which can hinder cooling and create hot spots and restrictions.
Scale and rust
____-blade fans were at one time considered the standard for non-air-conditioned rear-wheel drive vehicles.
Four-blade
The Canadian Enviromental Protection Act prohibited the production or importation of CFCs on January 1, 19__.
Most hydrochlorofluorocarbons (HFCs) such as R-22 will also be phased out in Canada by the year 20__
1996
2020
The rate of self-discharge of a battery increases as the temperature of the battery ________. Therefore, batteries are best stored in a ____ and dry location.
Increases
Cool
A positive plate is created by coating a lead-calcium plate grid with a very porous, brwon crystalline meterial called ____ peroxide (PbO2)
Lead
The water pump can circulate coolant at a rate as high as ____ gallons per hour.
7500
Expansion valves may be _______ or _______ equalized.
Internally or Externally
_______ is the force that causes electrons to flow.
Voltage
As refrigerant temperature increases, so does the pressure within the container. The _____ the temperature, the higher the pressure.
Higher
The temperature-sensing mechanism on a thermostatic fan clutch is a ______ spring.
Bimetallic
When the specific gravity is 1.___ or greater, the ball floats and the tube appears to have a green dot, which indicates a charged battery.
1.225
A receiver-dryer is located on the ____-pressure side of the system immediately downstream of the condenser and upstream of the ______ valve.
High-pressure
Expansion Valve
R-134a manifold gauges can be identified by ___ with a blackstripe (high side), ____ with a black stripe (low side) and ____ with a black stripe (utility)
Red
Blue
Yellow
Normally, valves with _______ equalizers are used on smaller evaporators, while valves with _______ equalizers are used on larger evaporators,
Internal
External
When removing or installing hoses, always carry out a good _____ inspection to determine whether they have wear or damage.
Visual Inspection
In the centre of the thermostat is a specially formulated ___ and ________ metal pellet that is tightly encased in a heat-conducting copper cup.
Wax
Powdered
A _______ occurs when a live conductor comes in contact with an electrical ground.
Ground
_____ pump removal and replacement is not common with most front-end crashes, although it may be required when there has been a severe frontal impact.
Water
Some electric fans have up to _____ blades and are usually made of _____.
Eight
Plastic
The same is true with refrigerant, but we only deal with only two states: ______ and _____.
Liquid and Vapour
______ links are one-time protection devices that melt to create an open circuit when current flow exceeds a certain level.
Fusible
For every __ C change in electrolyte temperature above or below 27 C, 0.00_ must be added or subtracted respectively from a specific gravity reading.
0.008
_______ are used in automotive circuitry to start, stop or redirect current flow.
Switches
A ______-______ circuit combines the features of series and parallel circuits.
Series-Parallel
______ is the amount of electron flow in a conductor. The unit of mesurement of current is the ______.
Current
Ampere
Though we use the word cold, it is a relative term that refers only to the absence of ____.
Heat
When cutting wire, never cut wire closer than __ mm (1.5”) from other splices or connectors.
40 MM
When the battery temperature is between 20 C and 30 C, the self discharge rate is approximately _._% of its charge per day
0.2%
________ is heat transfer through objects that are touching each other.
Conduction
The second function of a compressor is to compress the ___-pressure vapour to ____-pressure vapour.
Low-pressure
High-pressure
Manifold gauge sets are designed to take pressure reading when the hand valves are _____.
Closed
_______ belts require no adjustment, as tension is applied by the means of an automatic belt _______.
Serpentine
Tensioner
During dishcharge, a chemical reation is taking place within the battery. ____ from the electrolyte is converted into _____ and the specific gravity of the electrolyte decreases.
Acid
Water
A _____ circuit occurs when current takes a different path than was originally intended. If two or more conductors touch and current flows through that connection, a short circuit exists
Short circuit
Todays vehicles operate witg radiator caps that are designed to hold between __ psi and __ psi.
14psi
17 psi
The ______ the cross-sectioned area or diameter, the ____ resistance there is in similar types of conductors.
Larger
Less
The _______ cap provides functions for both pressure relief and vacuum relief and incorporates ___ valves in its constuction.
Radiator
Two
The ______ absorbs and stores any moisture that passes.
Desiccant
________ wiring is not used all that often in wiring harnesses.
Aluminum
Negative plate grids are constructed similar to positive plate grids. They are created by coating a lead-calcium plate grid with spongy _____ (Pb).
Lead
______ is the most common conductor used.
Copper
The condenser is made of _______ or copper.
Aluminum
______ to ground may occur when a bare wire is allowed to touch any metal component of the vehicle and creates an unwanted ground.
Short to ground
The boiling point of water at a sea level pressure of 14.7 psi is ___°C.
100°C
When recovering AC ensure that the addition of recovered refrigerant will not exceed __% of the conatiner’s gross weight rating.
80%
________ is done by vacuum-lowering the boiling point of the moisture, converting it to vapour (steam) and removing it.
Evacuating
Always wear goggles and _____ when doing work that involves opening the refrigeration.
gloves
Three terms relate to changing a liquid to a vapour or a vapour to a liquid: vaporization, ________ and condensation.
Evaporation
________ is opposition to flow of electrons. _______ is measured in ohms using an ohmmeter. The symbol for ohm is _.
Resistance
Resistance
Ω
A _____ ____ ________ (DVOM) is an electronic digital multimeter used to make electronic measurements,
Digital Volt Meter
______ gravity is a measurement of the density of a fluid or solid compared to that of water.
Specific
Strip approx _._mm (5/16”) of insulation from each wire to be spliced.
7.5mm
A _______ circuit has more than one current patch. It will consist of, at minimum, a voltage source, two or more resistances connected to the voltage source by seperate paths and connecting wire.
Parallel Circuit
A simple ______ circuit is the simplest type of circuit, providing only one path for current to flow.
Series
