Best Civil Engineer-3rd Year

Explanation
Tricalcium aluminate is the compound in cement that reacts the quickest with water. This is because tricalcium aluminate has a high reactivity and readily reacts with water to form calcium aluminate hydrates. This reaction is important in the initial setting and hardening of cement, as it contributes to the formation of a solid and durable structure.

Explanation
Improper mixing of concrete leads to honeycombing, which refers to the presence of voids or gaps in the concrete structure. This occurs when there is insufficient mixing or inadequate distribution of the ingredients, such as cement, aggregates, and water. As a result, the concrete does not fully bond together, leaving empty spaces that weaken the structure and reduce its durability. Honeycombing can also be caused by improper vibration during the pouring and compacting process, which further contributes to the formation of voids.

Explanation
Partially saturated soil is classified as three phase soil because it contains three phases: solid particles, water, and air. In this type of soil, the void spaces are partially filled with water and partially filled with air. The presence of these three phases affects the behavior and properties of the soil, such as its strength, permeability, and compressibility. Understanding the three phase nature of partially saturated soil is crucial in geotechnical engineering for analyzing and designing structures that interact with the ground.

Explanation
Negative skin friction is a phenomenon that occurs when a deep foundation, such as a pile, is embedded in soft clay. Soft clay has low shear strength and tends to deform under load. As the pile settles, the surrounding clay also settles, causing a drag force on the pile. This drag force, known as negative skin friction, acts in the opposite direction of the applied load and reduces the load-carrying capacity of the pile. Therefore, soft clay is known to cause negative skin friction in deep foundations.

Explanation
Carbon monoxide (CO) is the most dangerous pollutant in vehicular emissions because it is a colorless and odorless gas that is highly toxic to humans and animals. When inhaled, it binds to hemoglobin in the blood, reducing its ability to carry oxygen to the body's organs and tissues. This can lead to symptoms such as dizziness, headaches, and even death in high concentrations. Additionally, CO contributes to the formation of smog and is a major contributor to air pollution, which has detrimental effects on the environment and human health.

Explanation
Exposure to ultraviolet (UV) radiation from the sun can damage the DNA in skin cells, leading to the development of skin cancer. The ozone layer acts as a protective shield, absorbing most of the harmful UV radiation before it reaches the Earth's surface. However, depletion of the ozone layer allows more UV radiation to penetrate the atmosphere, increasing the risk of developing skin cancer. Therefore, the depletion of the ozone layer in the outer atmosphere is linked to the occurrence of skin cancer.

Explanation
The first Indian railway was laid in 1853.

Explanation
The mix proportion of M10 grade concrete is 1 part cement, 3 parts sand, and 6 parts aggregate. This means that for every unit of cement, there should be 3 units of sand and 6 units of aggregate in the mixture. This mix proportion is commonly used for non-structural purposes where a lower strength concrete is required. The ratio of 1:3:6 ensures a balanced mix that provides adequate strength and workability for the specific application.

Explanation
According to IS456 (Indian Standard Code of Practice for Plain and Reinforced Concrete), there are 7 grades of concrete mixes. These grades are M10, M15, M20, M25, M30, M35, and M40. Each grade represents the compressive strength of the concrete mix after 28 days of curing. The higher the grade, the stronger the concrete. These grades are used to determine the appropriate mix proportions and design of concrete for different construction applications.

Explanation
The BOD (Biochemical Oxygen Demand) of safe drinking water must be nil, 0, or zero. BOD is a measure of the amount of organic matter present in water, specifically the amount of oxygen required by microorganisms to decompose it. In safe drinking water, there should be no organic matter present, as it can indicate contamination and the potential presence of harmful microorganisms. Therefore, a BOD value of nil, 0, or zero is ideal for ensuring the safety and purity of drinking water.

Explanation
Percussion drilling involves repeatedly striking the rock surface to break it up and create a hole. This method is effective in unconsolidated or loosely packed rocks where the repeated impact can easily break them apart. However, in consolidated rocks, the particles are tightly packed and bonded together, making them more resistant to the impact of percussion drilling. Therefore, percussion drilling is unsuitable in consolidated rocks as it would not be able to effectively break them apart.

Explanation
Malaysia leads in the production of rubber due to its favorable climate and extensive rubber plantations. The country has a long history of rubber cultivation and has invested in advanced technologies and research to enhance production. Additionally, Malaysia has a well-developed infrastructure for rubber processing and export, making it a major player in the global rubber industry.

Explanation
Fathom is a unit of measurement used to determine the depth of water. It is commonly used in maritime and nautical contexts to measure the depth of oceans, seas, and other bodies of water. Therefore, the correct answer is depth.

Explanation
The central command of the army is located in Lucknow.

Explanation
Gobar gas, also known as biogas, is primarily composed of methane. Methane is a colorless and odorless gas that is produced through the decomposition of organic matter, such as animal waste or plant material, in the absence of oxygen. It is a highly flammable gas and can be used as a source of energy for heating, cooking, and electricity generation. Methane is the main component of gobar gas due to the anaerobic digestion process, where bacteria break down the organic matter and produce methane as a byproduct.

Explanation
Gravity setting chambers are used in industries to remove suspended particulate matter. These chambers rely on the force of gravity to separate the particulate matter from the gas stream. When the gas stream enters the chamber, it slows down, allowing the heavier particulate matter to settle to the bottom due to gravity. The settled particles can then be collected and removed from the chamber. This method is effective in removing larger particles that may be present in the gas stream, helping to improve air quality and reduce pollution.

Explanation
I.I.T Roorkee is considered the earliest engineering educational institution in India because it was established as the Thomason College of Civil Engineering in 1847, making it the oldest technical institution in the country. It has a rich history and has played a significant role in shaping engineering education in India.

Explanation
Vijay Singh is a professional golfer who hails from Fiji.

Explanation
Epoxy resins are commonly used as adhesives because of their strong bonding properties. They have excellent adhesion to a wide range of materials, including metals, plastics, and composites. Epoxy adhesives provide high strength and durability, making them suitable for various applications such as bonding components in the automotive, aerospace, and construction industries. They also offer resistance to chemicals, moisture, and heat, further enhancing their effectiveness as adhesives. Overall, epoxy resins are a popular choice for adhesives due to their reliable bonding capabilities and versatility.