SSC CGL Tier 1 2016 General Awareness Questions with Solutions

Explanation

In field hockey, a bully is a traditional method used to restart play after a stoppage that has no specific penalty associated with it, such as when the ball is stuck in a player's clothing or play is halted for an injury. During a bully, two opposing players stand over the ball with their sticks on the ground. They must tap the ground and then each other's sticks three times in alternation before they are permitted to strike the ball. Although modern rule changes have replaced the bully with a center pass for starting halves and after goals, it remains a distinct technical procedure within the sport's regulations.

Explanation

Sushil Kumar is a distinguished Indian freestyle wrestler who was honored with the Rajiv Gandhi Khel Ratna Award in 2009. This recognition followed his significant achievement at the 2008 Beijing Olympics, where he won a bronze medal in the 66 kg freestyle wrestling category. His success marked a major milestone for Indian wrestling, making him one of the few individuals to receive India's highest sporting honor for the discipline prior to 2016.

Explanation

Siderosis is a specific form of pneumoconiosis, an occupational lung disease, which is caused by the chronic inhalation of iron dust or iron oxide particles. The term originates from the Greek word sideros, meaning iron. This condition is typically found in workers engaged in iron mining, welding, iron milling, and steel manufacturing. Once inhaled, the iron particles accumulate in the pulmonary interstitium and are taken up by alveolar macrophages. On a chest X-ray, this deposition often appears as fine, dense, punctate shadows throughout the lung fields. While siderosis is often considered a benign condition because it does not typically lead to significant pulmonary fibrosis or functional impairment on its own, it serves as a clear indicator of heavy metal dust exposure in industrial environments.

Explanation

The term Doab is a Persian word where do translates to two and ab translates to water or river. Geographically, it refers to the fertile tract of land situated between two confluent rivers. This terminology is widely used in the Indian subcontinent to describe the alluvial plains found between major river systems, such as the famous Ganga-Yamuna Doab in northern India or the various doabs found in the Punjab region between the tributaries of the Indus River. These regions are characterized by high agricultural productivity due to the rich soil deposited by the flanking rivers.

Explanation

Nitrous oxide (N₂O), commonly known as laughing gas, is a colorless and non-flammable gas used in medical and dental procedures for its anesthetic and analgesic properties. When inhaled, it induces a state of relaxation and reduces the sensation of pain by interacting with the central nervous system. It is frequently administered in combination with oxygen to maintain safe levels of sedation during minor surgeries or dental work, as it has a rapid onset of action and is quickly eliminated from the body once inhalation stops.

Explanation

Cloves are the aromatic dried flower buds of the evergreen tree Syzygium aromaticum, which belongs to the Myrtaceae family. These buds are harvested during their immature stage when they transition from a pale green to a bright reddish color, just before the flowers actually bloom. Once collected, they are dried until they become dark brown and woody, a process that concentrates the essential oils, particularly eugenol, which gives the spice its distinct aroma and medicinal properties.

Explanation

Indonesia is not a member of the BRICS association. The grouping is exclusively composed of five major emerging national economies: Brazil, Russia, India, China, and South Africa. The acronym BRICS is derived from the first letter of each of these five member states. While Indonesia is a significant emerging economy and a member of other international forums like the G20, it was not part of the original BRIC group formed in 2006, nor did it join when the organization expanded to include South Africa in 2010.

Explanation

The slogan Do or Die was coined by Mahatma Gandhi during his speech at the Gowalia Tank Maidan in Mumbai on August 8, 1942. This speech formally launched the Quit India Movement, also known as the August Kranti. Through this call, Gandhi urged the people of India to make a final effort to secure independence from British rule, emphasizing that they must either free India or die in the attempt. The movement represented a decisive and intensified phase of the national struggle, demanding an immediate withdrawal of the British from Indian soil following the failure of the Cripps Mission.

Explanation

A parsec is a unit of length used to measure large distances to astronomical objects outside the Solar System. The name is a portmanteau of the words parallax and arcsecond. It is defined as the distance at which one astronomical unit subtends an angle of one arcsecond. In terms of other units, one parsec is approximately equal to 3.08 × 10¹⁶ meters, 206,265 astronomical units, or 3.26 light-years. This unit is fundamental in astronomy as it is derived from the trigonometric parallax method, which is the standard way to determine the distances of nearby stars by measuring their apparent displacement against more distant backgrounds as the Earth orbits the Sun.

Explanation

The term Angas, meaning limbs, refers to the primary collection of Jain canonical scriptures that constitute the core of the Jain Agamas. These texts contain the original teachings of Lord Mahavira, the 24th Tirthankara, which were systematically compiled and organized by his immediate disciples, known as Gandharas. Traditionally, there are twelve Angas, providing comprehensive guidance on Jain philosophy, ethics, conduct, and monastic rules. While the twelfth Anga, the Drishtivada, is believed to have been lost over time, the remaining eleven continue to serve as the fundamental authoritative scriptures for the Jain community, particularly within the Svetambara tradition.

Explanation

Dakshin Gangotri was established during the third Indian expedition to Antarctica in 1983-84 as India's first permanent scientific research base on the icy continent. Situated on the Princess Astrid Coast, the station provided a platform for conducting various scientific experiments in fields such as meteorology, glaciology, and magnetic studies. By 1990, the station was decommissioned and became an unmanned supply base after being buried under significant snow and ice accumulation. It was later succeeded by the Maitri and Bharati stations as part of the Indian Antarctic Programme.

Explanation

Open Market Operations (OMO) refer to the purchase and sale of government securities by the central bank, such as the Reserve Bank of India, in the open market. This is a primary instrument of monetary policy used to regulate the money supply and liquidity in the banking system. Fiscal policy, on the other hand, is managed by the government and focuses on revenue generation and expenditure. Because Open Market Operations are conducted by the central bank to influence interest rates and credit availability, they are classified as a monetary tool rather than a fiscal one.

Explanation

Mercury is the only metal that remains in a liquid state at standard room temperature and pressure. This unique property is a result of its electronic structure, specifically the relativistic contraction of the 6s orbital. This effect causes the valence electrons to be more strongly attracted to the nucleus than in other metals, leading to significantly weaker metallic bonding between mercury atoms. Because these atoms do not bind together strongly enough to form a solid crystal lattice at room temperature, mercury has an exceptionally low melting point of approximately -38.83 degrees Celsius.

Explanation

Phenol (C₆H₅OH) is an aromatic organic compound consisting of a phenyl group bonded to a hydroxyl group. It is commonly known as carbolic acid because it was historically derived from coal tar and exhibits weak acidic properties. In aqueous solution, phenol dissociates to form a phenoxide ion and a hydronium ion. This acidity is attributed to the resonance stabilization of the negative charge on the phenoxide ion, which is delocalized over the benzene ring. Due to its potent germicidal properties, carbolic acid was famously introduced as the first surgical antiseptic by Joseph Lister in the 1860s to sterilize medical instruments and clean wounds, significantly reducing post-operative infections.

Explanation

The Tehri Dam is a multi-purpose rock and earth-fill embankment dam located on the Bhagirathi River near Tehri in Uttarakhand. Standing at a height of 260.5 meters, it is the highest dam in India and ranks among the tallest in the world. The dam is the primary component of the Tehri Hydropower Complex, which includes a 1,000 MW reversible-pumped storage hydroelectricity station. The Bhagirathi River is one of the two main headstreams of the Ganges, originating from the Gangotri Glacier at Gaumukh in the Garhwal Himalayas. The dam creates a massive reservoir, known as Swami Ramtirth Sagar, which provides water for irrigation and municipal supply to several states in North India while regulating the flow of the river downstream.

Explanation

India shares its longest international land border with Bangladesh, covering a total distance of approximately 4,096.7 kilometers. This boundary is the fifth-longest land border in the world and traverses through five Indian states: West Bengal, Assam, Meghalaya, Tripura, and Mizoram. West Bengal shares the most significant portion of this frontier. The demarcation was originally based on the Radcliffe Line of 1947 and was further formalized and streamlined through the Land Boundary Agreement of 2015, which involved the exchange of territorial enclaves to resolve long-standing border disputes. The border encompasses a wide variety of landscapes, including fertile plains, riverine tracts, and hilly regions.

Explanation

Gujarat possesses the longest coastline of any Indian state, measuring approximately 1,214.7 kilometers. This extensive shoreline accounts for nearly 24 percent of India's total mainland coastline. The significant length is primarily due to the state's unique geographical features, including the presence of the Kathiawar peninsula and two major inlets of the Arabian Sea: the Gulf of Kachchh and the Gulf of Khambhat. These indentations and the curved nature of the shoreline significantly increase the total coastal distance compared to states with more linear boundaries.

Explanation

In a perfect competition market structure, an individual firm is a price taker because it has no power to influence the market price of the product it sells. This occurs because the market consists of a very large number of small firms producing homogeneous or identical products, and consumers have perfect information. The price is determined solely by the market forces of aggregate demand and supply. Since any single firm produces only a negligible fraction of the total market output, increasing or decreasing its own supply has no perceptible impact on the equilibrium price. Consequently, the firm faces a perfectly elastic demand curve, which is represented as a horizontal line at the market price level where P = MR = AR. If a firm attempts to raise its price even slightly above the market rate, it will lose all its customers to competitors who are selling the exact same product at the lower market price.

Explanation

Tropical evergreen forests thrive in regions characterized by high annual rainfall, generally exceeding 200 cm, and high temperatures throughout the year. In India, the Western Ghats represent one of the primary zones for this vegetation type. The mountain range intercepts the moisture-laden Southwest Monsoon winds, leading to heavy orographic precipitation on the windward side. These conditions support a dense, multi-layered canopy where trees such as rosewood, mahogany, and cinchona remain green throughout the year because there is no prolonged dry period to trigger simultaneous leaf shedding across all species.

Explanation

Creatinine is a nitrogenous waste product generated from the normal breakdown of creatine phosphate in muscle tissue. It is produced at a relatively constant rate by the body and is primarily cleared from the bloodstream by the kidneys through glomerular filtration. Because it is neither significantly reabsorbed nor extensively secreted by the renal tubules, creatinine is a standard and expected component of healthy human urine. Its concentration in the urine is often used as a clinical indicator to measure the glomerular filtration rate and evaluate overall renal function.

Explanation

Japan is geographically situated on the eastern edge of the Eurasian continent. Because the Earth rotates from west to east, regions located further east experience the sunrise before those to the west. From the historical perspective of ancient China, Japan was the land located in the direction where the sun originated, leading to the name Nihon, which literally translates to sun origin. Being one of the first major nations to witness the sunrise each day in the Far East, it is traditionally referred to as the Land of the Rising Sun.

Explanation

The thymus gland, located in the upper thoracic region behind the sternum, is an essential part of the immune and endocrine systems. It secretes a group of peptide hormones collectively known as thymosin. This hormone plays a vital role in the differentiation and maturation of T-lymphocytes, also called T-cells, which are central to cell-mediated immunity. Additionally, thymosins promote the production of antibodies to provide humoral immunity. The gland is most active during childhood and gradually undergoes atrophy after puberty, leading to a decrease in thymosin production in older individuals.

Explanation

The ABO blood group system is classified based on the presence or absence of inherited antigenic substances on the surface of red blood cells and corresponding antibodies in the blood plasma. Individuals with blood group AB have both antigen A and antigen B present on the surface of their erythrocytes. Consequently, their plasma does not produce anti-A or anti-B antibodies. If these antibodies were present, they would recognize the A or B antigens on the individual's own red blood cells as foreign and cause them to clump together, a process known as agglutination. The lack of these antibodies in the plasma is what allows individuals with blood group AB to safely receive red blood cells of any ABO blood type, earning them the designation of universal recipients.

Explanation

Vitamins are classified into two categories: water-soluble and fat-soluble. Vitamins A and D are fat-soluble vitamins, which means they are absorbed along with fats in the diet and stored in the liver and fatty tissues for long periods. Because these vitamins are not easily excreted by the body, excessive intake through supplements can lead to a condition called hypervitaminosis. High levels of Vitamin A can cause liver damage, intracranial pressure, and bone pain, while an excess of Vitamin D leads to hypercalcemia, which results in the deposition of calcium in soft tissues like the kidneys and heart, potentially causing permanent organ damage. This ability to accumulate in the body's storage sites makes them more likely to reach toxic levels compared to vitamins that are regularly flushed out through urine.

Explanation

An atomic explosion is the result of an uncontrolled nuclear fission chain reaction. When a sufficient amount of fissile material, such as Uranium-235 or Plutonium-239, reaches a supercritical mass, a single neutron can trigger a fission event that releases multiple additional neutrons. These neutrons then strike other nuclei, causing them to fission and release even more neutrons. In an uncontrolled chain reaction, this process accelerates exponentially in a fraction of a microsecond, releasing a massive amount of energy instantaneously in the form of heat, light, and radiation, leading to a violent explosion. Unlike steady-state reactions where the neutron population is kept constant, the lack of regulation in an uncontrolled reaction allows the energy output to grow without limit until the fuel is physically dispersed by the force of the blast.

Explanation

Refraction is the physical phenomenon where the direction of a light ray changes as it crosses the boundary between two media of different optical densities. This occurs because light travels at different speeds in different substances; for instance, light travels faster in air than in water or glass. As the wave front enters the second medium at an angle, one side of the wave changes speed before the other, causing the entire ray to pivot or bend. The relationship between the angle of incidence ₁, the angle of refraction ₂, and the refractive indices n₁ and n₂ of the media is defined by Snell’s Law: n₁ sin ₁ = n₂ sin ₂.

Explanation

Under Article 110(3) of the Constitution of India, if any question arises regarding whether a Bill is a Money Bill or not, the decision of the Speaker of the Lok Sabha is final. This constitutional authority ensures that the Speaker has the exclusive power to certify such bills. Furthermore, Article 110(4) requires that when a Money Bill is transmitted to the Rajya Sabha or presented to the President for assent, it must carry a certificate signed by the Speaker confirming its status as a Money Bill. This decision is conclusive and cannot be questioned in any court of law, by either House of Parliament, or by the President.

Explanation

The Reserve Bank of India launched the Sachet portal in August 2016 as a dedicated platform to curb illegal money collection and unauthorized deposit-taking activities. The website enables members of the public to verify whether a specific financial entity is registered with any regulator and authorized to accept deposits. It also provides a mechanism for individuals to lodge complaints and share information regarding fraudulent schemes or companies illegally soliciting money. Furthermore, the portal facilitates enhanced coordination and data sharing between various financial regulators and state government departments under the State Level Coordination Committee framework to ensure timely action against unscrupulous entities.

Explanation

Opera is a multi-platform web browser developed by Opera Software. It is classified as application software designed to retrieve, traverse, and present information resources on the World Wide Web. Unlike an operating system, which serves as the primary system software managing computer hardware and providing common services for other programs, Opera must be installed and run on top of an existing operating system to function. By 2016, it was recognized globally for features such as its integrated search bar, tabbed browsing, and data compression technology, rather than as a system-level interface between hardware and users.

Explanation

Bezwada Wilson and T.M. Krishna were the two Indian recipients of the Ramon Magsaysay Award in 2016. Bezwada Wilson, the national convener of the Safai Karmachari Andolan, was recognized for his decades-long crusade to eradicate the practice of manual scavenging and for asserting the fundamental right to human dignity. T.M. Krishna, a distinguished Carnatic vocalist, was honored for his role in breaking social barriers and democratizing the arts by making classical music accessible to all levels of society, thereby using culture as a powerful tool for social inclusion and healing.

Explanation

Under Article 200 of the Indian Constitution, the Governor is vested with the power to grant assent, withhold assent, or reserve a bill for the President's consideration. However, this power is specifically limited by the first proviso of the article. If the Governor returns a bill (other than a Money Bill) to the State Legislature for reconsideration and the House passes the bill again, with or without amendments, the Governor is constitutionally mandated to give his assent. Unlike situational discretions regarding the executive, this provides a clear legal boundary where the Governor's personal judgment or delay cannot override the final decision of the elected legislature. Furthermore, the Governor generally acts on the aid and advice of the Council of Ministers in matters of legislation, making the exercise of independent discretion in granting assent an exception rather than the rule.

Explanation

Captain William Hawkins was the first Englishman to visit the Mughal court of Emperor Jahangir, arriving in Agra in 1608. He traveled as a representative of the English East India Company on the ship Hector and carried a letter from King James I of England seeking trade permissions and the establishment of a factory at Surat. Hawkins was able to communicate directly with Jahangir in Turkish, which impressed the Emperor. Consequently, Jahangir granted him a mansab of 400 and bestowed upon him the title of English Khan. Hawkins remained at the Mughal court until 1611, laying the groundwork for future diplomatic and commercial relations between England and the Mughal Empire.

Explanation

Article 76 of the Constitution of India provides for the office of the Attorney General for India, who is the highest law officer in the country. Appointed by the President, the Attorney General acts as the chief legal advisor to the Government of India and is responsible for performing duties of a legal character assigned by the President. This official has the right of audience in all courts within the territory of India and participates in the proceedings of both Houses of Parliament without the right to vote. The Attorney General represents the Union Government in all cases in the Supreme Court and any High Court in which the Government of India is concerned.

Explanation

According to Article 280 of the Constitution of India, the Finance Commission is a constitutional body that is constituted by the President of India every five years or at such earlier time as the President considers necessary. The commission is mandated to provide recommendations on the distribution of net proceeds of taxes between the Union and the States, as well as the allocation among the States themselves, for a defined period of five years.

Explanation

The Narmada Water Disputes Tribunal (NWDT) was established by the Government of India on October 6, 1969, under the Inter-State River Water Disputes Act of 1956. The tribunal was constituted to adjudicate the dispute over the sharing of the Narmada River waters and the development of the river valley, specifically concerning the height of the Sardar Sarovar Dam. The four states involved in this water-sharing agreement are Gujarat, Maharashtra, Rajasthan, and Madhya Pradesh. Although the Narmada river does not flow through Rajasthan, that state was included as a beneficiary for irrigation purposes. The tribunal issued its final award in 1979, which allocated the utilizable quantum of Narmada waters among these four states and determined the height of the dam.

Explanation

Article 258(1) of the Constitution of India empowers the President to entrust Union functions to a State Government. According to this provision, the President may, with the consent of the Government of a State, entrust either conditionally or unconditionally to that Government or to its officers functions in relation to any matter to which the executive power of the Union extends. This provision facilitates administrative cooperation between the Center and the States, allowing the Union to utilize the administrative machinery of the State for the execution of its executive powers, provided the State Government agrees to the arrangement.

Explanation

The National Rail Museum is located in Chanakyapuri, New Delhi. It was inaugurated on February 1, 1977, to preserve and showcase the rich heritage of the Indian Railways. Spanning over 10 acres, the museum features a vast collection of over 100 life-size exhibits, including historic steam, diesel, and electric locomotives, royal carriages, and vintage signaling equipment. Among its most prominent exhibits is the Fairy Queen, one of the oldest functional steam engines in the world, alongside various luxury saloons used by Indian royalty and the Viceroys of India.

Explanation

The Ajanta Caves are renowned for their rich and detailed frescoes that extensively depict various species of flora and fauna alongside human figures and Jataka tales. Therefore, the statement that they do not contain paintings of flora and fauna is false.

Explanation

Swami Dayanand Saraswati founded the Arya Samaj on 10 April 1875 in Bombay to reform Hindu society and promote the supreme authority of the Vedas. He championed the slogan Back to the Vedas and aimed to purge Hinduism of superstitious practices, idol worship, and social evils like untouchability and child marriage. His seminal work, Satyarth Prakash, detailed his philosophy of monotheism and Vedic education, leading to the establishment of various educational institutions known as Dayanand Anglo-Vedic (DAV) schools.

Explanation

Bharatendu Harish Chandra is widely regarded as the father of modern Hindi literature and Hindi theatre. While his literary works often reflected the socio-political consciousness of the 19th century and expressed patriotic sentiments against British rule, his primary contribution was the modernization of the Hindi language and the development of new literary genres. He played a pivotal role in transitioning Hindi literature from the traditional devotional and erotic themes of the Riti period to modern realism. Unlike leaders who founded institutionalized movements for religious purification or social restructuring, Harish Chandra focused on cultural and linguistic revivalism through journalism, poetry, and drama.

Explanation

Direct taxes are those levied by the government directly on the income, wealth, or profits of individuals and corporate entities. The fundamental characteristic of a direct tax is that the impact and the incidence of the tax fall on the same person; the burden cannot be shifted to another party. Consequently, the most immediate and significant effect of a direct tax, such as personal income tax or corporate tax, is the reduction of the taxpayer's disposable income. Disposable income is the net amount available for spending or saving after all direct taxes have been deducted from the gross income, expressed by the relation Y_d = Y - T. By directly decreasing this surplus, direct taxes serve as a key instrument for regulating private consumption and managing income inequality within an economy.

Explanation

Under Article 85(2)(a) of the Constitution of India, the President is vested with the power to prorogue either House of Parliament. While the presiding officer adjourns the House to suspend a specific sitting, prorogation terminates an entire session of the House. This executive power is exercised by the President on the advice of the Council of Ministers headed by the Prime Minister. Typically, after the Speaker adjourns the Lok Sabha sine die upon the completion of the session's business, the President issues a notification to officially prorogue the House.

Explanation

The Portuguese were the first Europeans to reach India by sea, marking the beginning of the era of European colonial presence in the subcontinent. This was achieved when the Portuguese explorer Vasco da Gama landed at Calicut on the Malabar Coast on May 20, 1498. He discovered the direct sea route from Europe to India via the Cape of Good Hope. Following this successful voyage, the Portuguese established their first trading post at Cochin and later made Goa the capital of their Indian territories in 1510. Their arrival significantly predated other European powers, establishing a dominance in the Indian Ocean trade that lasted throughout the 16th century.

Explanation

Dumping is a form of international price discrimination where a company exports a product to a foreign market at a price significantly lower than its domestic price or lower than its cost of production. In the context of economic theory, this often manifests as selling a commodity in an overseas market at a price below its marginal cost. The strategy is typically employed to penetrate a new market, dispose of surplus production, or eliminate competition in the target country to eventually establish a dominant position. By pricing goods below the marginal cost of production, the exporter can undercut local manufacturers who cannot sustain such low price levels. This practice is regulated under the World Trade Organization (WTO) agreements, which allow member nations to impose anti-dumping duties if they can demonstrate that the imported goods are being dumped and are causing material injury to the domestic industry.

Explanation

The Sun shines vertically on the Equator twice a year during the equinoxes. These events occur around March 21, known as the Vernal or Spring Equinox, and around September 23, known as the Autumnal Equinox. During these specific points in Earth's orbit, the tilt of the Earth's axis is not inclined toward or away from the Sun, causing the subsolar point to cross the Equator. Consequently, the solar declination is 0°, and the Sun's rays strike the equatorial surface at a 90° angle at noon, resulting in nearly equal day and night lengths across the entire planet.

Explanation

Lichens are complex organisms that exist as a symbiotic association between a fungus and an algae or cyanobacterium. This relationship is a form of mutualism where both partners benefit from each other. The fungal partner, referred to as the mycobiont, forms the majority of the lichen's physical bulk and provides a protected environment, structural support, and absorbs water and essential minerals from the surroundings. The algal partner, known as the photobiont, possesses chlorophyll and performs photosynthesis to manufacture organic food (carbohydrates) for the entire association. This specialized partnership allows lichens to colonize extreme environments, such as bare rocks and arctic tundras, where the individual components would struggle to survive independently.

Explanation

Milk is considered a nearly complete food because it contains a balanced mix of proteins, fats, carbohydrates, and minerals. However, it is naturally deficient in Vitamin C and iron. Vitamin C, or ascorbic acid, is primarily found in citrus fruits and green leafy vegetables. The negligible amount of Vitamin C that may be present in raw milk is usually destroyed during the pasteurization process, as the vitamin is highly sensitive to heat and oxidation. Therefore, milk does not serve as a reliable dietary source for this nutrient.

Explanation

The pepper plant, scientifically known as Piper nigrum, is a perennial woody vine belonging to the family Piperaceae. It is a climbing plant that utilizes aerial roots to anchor itself to supporting structures such as trees, poles, or trellises, often reaching heights of four meters or more. Native to the tropical forests of South India, its growth habit is characterized by trailing stems that root easily at the nodes. This climbing nature allows the plant to ascend toward sunlight in dense forest environments, producing the flower spikes that eventually yield the small drupes known as peppercorns.

Explanation

Newton's third law of motion states that for every action, there is an equal and opposite reaction. When a cannon fires a shell, the explosion of the propellant exerts a massive forward force on the projectile to accelerate it out of the barrel. Simultaneously, the projectile exerts an equal force back onto the cannon in the opposite direction. This backward force causes the cannon to move in the direction opposite to the shell's trajectory, a phenomenon known as recoil. The force pair ensures that the total momentum of the system remains constant, but the immediate cause of the backward motion is the reactive force described by Newton's third law.

Explanation

In the relational model of databases, a candidate key is defined as a minimal set of attributes that can uniquely identify a tuple within a relation. A table may have one or more candidate keys. From this set of available candidate keys, the database designer selects one to function as the primary key for the table. Because the primary key is specifically chosen from the existing pool of candidate keys, it inherently possesses all the properties of a candidate key, such as uniqueness and minimality. Therefore, every primary key is by definition a candidate key.