FREE Bachelor of Civil Engineering Questions and Answers

Question 1

Which of the following methods is used to obtain lime?

Accepted Answer

Burning limestone

Answer

Lime (calcium oxide, CaO) is primarily obtained through a process called calcination, which involves heating limestone (calcium carbonate, CaCO3) to high temperatures (around 900-1000°C) in a kiln. This thermal decomposition reaction drives off carbon dioxide, leaving behind calcium oxide. This process is fundamental to the production of lime for various industrial applications.

Question 2

Which of the ensuing pairings is correctly matched?

Accepted Answer

Class B – Mortar

Answer

Class B lime is specifically known as semi-hydraulic lime, which possesses properties suitable for masonry mortars and plasters. It sets slowly in air and also under water, providing good workability and strength for these construction applications. This classification helps distinguish it from other lime types used for different purposes, such as Class A for finishing or Class D for structural work.

Question 3

Pure limestone is calcined to produce a substance known as:

Accepted Answer

Quick Lime

Answer

Calcination is the process of heating pure limestone (calcium carbonate, CaCO₃) to a high temperature, typically around 900-1000°C. This thermal decomposition reaction drives off carbon dioxide (CO₂), leaving behind calcium oxide (CaO). Calcium oxide is commonly known as quicklime or unslaked lime, a highly reactive substance used in various industrial and construction applications.

Question 4

How is the configuration in a clamp if coal is the fuel?

Accepted Answer

Heaped

Answer

In a clamp, which is a traditional and often temporary method for burning bricks, coal as fuel is typically arranged in a heaped configuration. This involves placing layers of bricks interspersed with layers of coal, with the coal often piled up or distributed unevenly. This arrangement facilitates the slow and continuous burning of the fuel, transferring heat to the bricks for their firing process.

Question 5

How can one comprehend the finish of lime burning?

Accepted Answer

Blue flame at the top disappears

Answer

During the calcination of limestone, the presence of a blue flame at the top of the kiln indicates the burning of carbon monoxide (CO) gas, which is produced as an intermediate product or from incomplete combustion. When the calcination process is complete, and all the limestone has been converted to quicklime, the production of these combustible gases ceases. The disappearance of this blue flame serves as a visual indicator that the burning process has reached its desired conclusion.

BE/B Eng Bachelor of Engineering Practice Test

BE/B Eng Bachelor of Engineering Practice Test

FREE Bachelor of Civil Engineering Questions and Answers