Previous Year UPSC Questions

Explanation

The Amazon River is the longest river among the given options. The Amazon River flows through South America, mainly in Brazil, Peru, and Colombia. It has the largest discharge volume of any river in the world. Some sources debate whether the Amazon or the Nile is the longest river, but in this set of options, Amazon is the longest. Comparison of the approximate lengths of the given rivers:

Amazon River: 6,992 km (4,345 miles)(approximately) Amur River: 4,444 km (2,763 miles) Congo River: 4,700 km (2,922 miles) Lena River: 4,400 km (2,736 miles)

Explanation

The largest coral reef in the world is the Great Barrier Reef, which is located off the coast of Australia. The Great Barrier Reef is the world’s largest coral reef system, stretching over 2,300 km (1,400 miles) along the north-east coast of Australia in the Coral Sea. It consists of over 2,900 individual reefs and 900 islands. It is visible from space and is one of the Seven Natural Wonders of the World. It is a UNESCO World Heritage Site and a crucial ecosystem, home to diverse marine life.

Explanation

Glenn McGrath, with 563 wickets in 124 matches, was the leading fast-bowling wicket-taker. Wasim Akram (414 wickets in 104 Tests) and Richard Hadlee (431 wickets in 86 Tests) were among the greatest fast bowlers. Courtney Walsh became the first bowler to cross 500 wickets, finishing with 519 in 132 Tests.

Explanation

Parimarjan Negi is a renowned Indian chess grandmaster. He became a Grandmaster (GM) in 2006 at the age of 13 years and 4 months, making him the youngest Indian to achieve the GM title at that time.

Explanation

Statement 1 is correct: The Visakhapatnam Steel Plant (RINL), also known as Vizag Steel, is a prominent integrated steel producer located in Visakhapatnam, Andhra Pradesh, India. By the year 2007, RINL had been granted "Mini Ratna" status by the Indian government. This designation recognizes the company’s strong performance and gives it greater autonomy in financial and operational decision-making.

Statement 2 is correct: In 2006, The Indian Iron and Steel Company (IISCO), formerly an independent entity, was successfully merged with the Steel Authority of India Limited (SAIL). SAIL, a major public sector steel producer in India, undertook this merger to consolidate its operations, enhance efficiency, and streamline its production processes. The merger of IISCO with SAIL has integrated the resources and expertise of both organizations, creating a larger and more robust entity within the Indian steel sector.

Explanation

Muhammad bin Tughlaq (reigned 1325-1351) was a controversial Sultan of Delhi known for his ambitious yet often failed policies, including the introduction of token currency and the shifting of the capital to Daulatabad. While his reforms aimed at modernizing administration, they led to economic instability and widespread discontent. Assertion (A) is correct: Muhammad bin Tughlaq introduced a variety of coins during his reign, including a gold coin referred to as the Dinar by Ibn Batutah. His interest in monetary innovations is well-documented. Reason (R) is incorrect: Muhammad bin Tughlaq’s plan to introduce token currency was implemented using copper and brass coins, not gold. The intention behind issuing token currency was to address a shortage of precious metals and not to promote trade with West Asian and North African countries.

Explanation

Assertion (A) is False: Mars takes a longer time than Earth to orbit the Sun. The time taken by a planet to orbit around the Sun is called its orbital period or year. Mars has an orbital period of about 687 Earth days which means it takes 687 days to complete one revolution around the Sun. Earth takes 365.25 days (about 365 days) to complete one revolution around the Sun. Reason (R) is True: Mars does have a smaller diameter than Earth. The diameter of Earth is 12,742 km. The diameter of Mars is 6,779 km (almost half of Earth). The time taken by a planet to orbit the Sun depends on its distance from the Sun, not its diameter. Since Mars is farther from the Sun than Earth thus it has a longer orbital period.

Explanation

The Lodi Dynasty (1451-1526) was the last Afghan ruling dynasty of the Delhi Sultanate. It was founded by Bahlol Lodi, Which marked the beginning of Afghan rule in Delhi, and ended with the defeat of Ibrahim Lodi at the First Battle of Panipat, which led to the establishment of the Mughal Empire.

Option (c) is correct The correct chronological order of the rulers of the Lodi dynasty are as follows:

Bahlol Khan Lodi (1451-1489) established Afghan rule in Delhi after overthrowing the Sayyid Dynasty. Sikandar Shah Lodi (1489-1517)was son of Bahlol Lodi. He is known for administrative efficiency and establishing the city of Agra in 1504. Ibrahim Lodi (1517-1526) was son of Sikandar Lodi.His defeat by Babur at the First Battle of Panipat (1526) marked the end of the Delhi Sultanate and the beginning of the Mughal Empire.

Explanation

Enzyme-linked immunosorbent assay (ELISA) is a laboratory technique that detects and measures the amount of specific substances in a solution.

Statement 1 is incorrect: The ELISA (Enzyme-Linked Immunosorbent Assay) test is primarily used to detect the presence of antibodies or antigens in the blood, and it is widely employed for diagnosing infections such as HIV, rather than cancer. It is not the first or basic test for cancer detection. Cancer is typically diagnosed using imaging techniques (e.g., MRI, CT scans), biopsies, or specific blood marker tests.

Statement 2 is incorrect: The Rh factor, also known as the Rhesus factor, is a protein that can be present on the surface of red blood cells. Individuals with this protein are classified as Rh-positive (Rh+), while those without it are Rh-negative (Rh-). Globally, the distribution of Rh factor is not evenly split. Approximately 94% of the world’s population is Rh-positive, and only about 6% is Rh-negative. This distribution varies among different populations and regions.

Explanation

The invasions of ancient India by the Greeks, Sakas, and Kushanas occurred between the 4th century BCE and the 2nd century AD, marking significant cultural and political shifts in the Indian subcontinent due to the introduction of Hellenistic, Central Asian, and nomadic influences.

Option (a) is correct:

Greeks: In the 4th century BCE, Alexander the Great initiated the Greek invasions into India. After his death, his Indian conquests we taken over by the Seleucids and then by the Greeks of Bactria. Sakas: The Sakas, or Scythians, were a group of nomadic tribes from Central Asia who invaded north-western India in the 2nd century BC, following the path set by the Greeks. Kushanas: The Kushans, originally from Central Asia (modern China), invaded India from the 1st to the 3rd century AD.