This set of Automotive Engine Auxiliary Systems online test focuses on “Coolants”.
1. The additives which are added to lower the Freezing point of the coolant is ______
a) anti- Knocking Agent
b) temperature controller
c) anti freezer
Explanation: The Anti-Freezer additive lowers the freezing point of water which helps when the temperatures fall very low. Even for hot climates, the use of antifreeze has the incidental advantage that the boiling point of the cooling water is raised.
2. The ratio of Ethylene glycol and Water in the coolant is ______
Explanation: Ethylene glycol keeps hoses and seals smooth and raises the coolant’s boiling point. The ratio of Ethylene glycol in water is 50:50 as it must be in balance for the evaporation of water when the engine temperature increases.
3. The qualities of the Anti-freezer must have these Qualities ______
a) average Viscosity
b) no corrosive property
c) must be Miscible
d) all of the above
Explanation: The coolant must be Miscible with water and should not be Corrosive when the coolant flows through the jackets and should have average viscosity.
4. Carboxylates are added in the Coolant to prevent from ______
Explanation: Carboxylate inhibitors provide corrosion protection by chemically interacting with the metal surfaces where needed, not by universally laying down layers.
5. ______ Meter is used to measure the Glycol and water ratio present in the coolant?
Explanation: Refractometer is used to measure the glycol water ratio because it offers the best method to identify the precise glycol content of the coolant.
6. The pH range of Coolant is ______
a) equal to or Greater than 7
Explanation: pH is a scale used to find how acidic or basic a given solution is. Acidic solutions have a lower pH, while basic solutions have a higher pH. Coolant operates in neutral or basic conditions as they should not react with the metals they travel through. So equal to or greater than 7 is preferred.
7. The coolant is made up of three components they are ______
a) water, anti-freezer and SCA’s
b) water, fuel, and silicates
c) water, buffers and SCA’s
d) water, SCA’s and defoamers
Explanation: The coolant consists of water and anti-freeze in proper proportion with a small amount of SCA’s. The antifreeze does not let the coolant to freeze in cold climates and the SCA’s helps in the life and health of the engine, especially older equipment.
8. The boiling point of ethylene glycol used in the coolant is ______Degree Centigrade
Explanation: The boiling point is the temperature at which the vapor pressure of a chemical equals atmospheric pressure. The boiling point of ethylene glycol is 195-degree Centigrade and used as coolant in automobiles. The higher boiling point indicates greater intermolecular force therefore less vapor pressure.
9. In a 50% concentration of ethylene glycol (by volume) lowers the freezing point of water to ______Degree Centigrade.
Explanation: Ethylene glycol interferes with the hydrogen bonding network in pure water. Water freezes at 0°C and pure ethylene glycol at -12°C, due to which 50% concentration of ethylene glycol lowers the freezing point of water to -37 degrees centigrade.
10. The coolant used in heavy-duty engines should be______
a) green in color
b) fully formulated
Explanation: The Coolant for a heavy-duty engine will be fully formulated adopts a propylene glycol and ethylene glycol as the basic liquid.
11. The abbreviation of SCA is ______
a) supplemental Coolant Additive
b) super Cooling Additive
c) standard Coolant Additive
d) strategic Chemical Additive
Explanation: SCA is vital for the health and longevity of any diesel engine and its abbreviation is supplemental Coolant Additive. The advantages of SCA is it extends the life and health of the engine, especially older equipment, and also aid in preventing cavitation and pitting in diesel engines.
12. The boiling point of the coolant should be ______
d) none of the above
Explanation: The boiling point of them should be high thereby minimum loss due to evaporation and the coolant can be operated at the higher temperature.
13. The anti-freeze should have ______specific heat capacity to be compared to the specific heat capacity of the coolant.
Explanation: The anti freezer plays a critical role in sustaining engine heat balance by removing heat. The main requirement of an anti-freeze is that it should have a high specific heat capacity when compared to that of the coolant.
Sanfoundry Global Education & Learning Series – Automotive Engine Auxiliary Systems.
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