Rate this page

The uppermost ring on a piston is usually plated with, multiple choice question is given below:

Q. The uppermost ring on a piston is usually plated with

(a) steel
(b) cast iron
(c) aluminium
(d) chromium

Ans:  (d) chromium    


Download Sample: Automobile Engineering MCQ PDF 2nd Edition.pdf

Refresh the page if PDF preveiw shows error.

Explanation of mcq The uppermost ring on a piston is usually plated with is given below:

The uppermost ring on a piston is usually plated with chromium, and this practice has become a standard in modern engine design. Chromium plating of the piston ring serves several important purposes and offers numerous benefits in terms of engine performance, durability, and longevity.

One of the primary reasons for plating the uppermost ring with chromium is to enhance its durability and wear resistance. The combustion chamber of an engine experiences extreme conditions, including high temperatures, pressures, and chemical reactions. The top compression ring, located closest to the combustion chamber, is subjected to intense heat and pressure cycles with each combustion event.

Chromium plating provides a hard and smooth surface on the ring, which helps it withstand these harsh conditions and reduces wear and tear over time. This plating process creates a thin layer of chromium on the surface of the ring, which offers excellent resistance to corrosion and abrasion.

Moreover, chromium plating also contributes to reducing friction between the piston ring and the cylinder wall. The piston rings form a seal against the cylinder wall, preventing the escape of gases during combustion and maintaining optimal compression within the combustion chamber.

By reducing friction, the chromium plating minimizes the energy losses caused by the piston ring-cylinder wall interaction. This leads to improved engine efficiency, reduced fuel consumption, and enhanced overall performance.

In addition to durability and reduced friction, chromium plating offers other advantages. The smooth surface created by the plating process promotes efficient lubrication and reduces the chances of oil consumption by preventing oil from entering the combustion chamber. This helps maintain proper lubrication of the piston ring and extends its lifespan.

Furthermore, chromium plating also contributes to the prevention of rust and corrosion, enhancing the longevity of the piston ring.

It’s important to note that while the uppermost ring is typically plated with chromium, other rings on the piston may have different plating materials or coatings based on their specific functions.

For example, the second ring from the top may have a molybdenum coating to provide excellent oil retention properties, while the oil control rings may have a different type of plating or coating to enhance their oil-scraping capabilities.

In conclusion, the use of chromium plating on the uppermost ring of a piston brings several benefits to engine performance. It enhances the durability and wear resistance of the ring, reduces friction between the piston ring and the cylinder wall, promotes efficient lubrication, and prevents rust and corrosion.

These advantages contribute to improved engine efficiency, reduced fuel consumption, and extended lifespan of the piston ring, making it an essential component in modern engine design.

Q. The frame may get distorted to a parallelogram shape due to
(a) weight of vehicle
(b) weight of passengers
(c) cornering force
(d) wheel impact with road obstacle

Q. By using synchronizing device, the two involved adjacent gears have their speeds
(a) increased
(b) reduced
(c) equalized
(d) unequalised

Q. The maximum intensity of pressure which the clutch facing can withstand without being damaged is about
(a) 10 Pa
(b) 10 kPa
(c) 100 kPa
(d) 1000 kPa

Leave a Reply

Your email address will not be published. Required fields are marked *

Shopping Cart
Scroll to Top
Talk to Me
Hi, Ask me anything regarding your exam
Scan the code
Help Desk
Hi, Ask me anything regarding your exam preparation.