BCA (General Knowledge)

GDR stands for Global Depository Receipt, which represents shares of a foreign stock held by a bank. The 'D' specifically stands for 'Depositary' or 'Depository' referring to the bank that holds the underlying shares and issues the receipts, though 'Deposit' is commonly used in some contexts.

The Euro was established as the official single currency for the European Union, introduced to facilitate trade and economic integration among member nations. It replaced national currencies like the German Mark and French Franc, creating a unified monetary system across Eurozone countries.

Coulomb's law states that electrostatic force is inversely proportional to the square of the distance between charges. When distance is halved (divided by 2), the force increases by the square of that factor - 2² = 4 times. This inverse square relationship is fundamental in electrostatics.

C-DOT (Centre for Development of Telematics) is the premier research and development organization of the Government of India dedicated to telecommunications technology.

Kathakali is a classical dance-drama from Kerala, known for its elaborate costumes, colorful makeup, and stylized movements. It combines elements of dance, drama, music, and ritual, traditionally performed in temple contexts. While other states have rich dance traditions, Kathakali originated and is specifically associated with Kerala.

The Gulf War (1990-1991) was fought between Iraq and a US-led coalition of allied forces including 35 countries. The conflict began with Iraq's invasion of Kuwait and culminated in Operation Desert Storm, where American and allied forces liberated Kuwait. The coalition included NATO members, Arab states, and other international partners.

Field Marshal is the highest rank in the Indian Army, a five-star general officer rank appointed only in exceptional circumstances. The Navy has Admiral of the Fleet as its equivalent highest rank, while the Air Force has Marshal of the Air Force.

One coulomb is the amount of charge transferred when a current of one ampere flows for one second. This is expressed by the formula Q = I × t, where Q is charge in coulombs, I is current in amperes, and t is time in seconds.

Electricity consumption for homes is measured in kilowatt-hours (kWh), commonly called 'units'. One kilowatt-hour represents the energy consumed by a 1000-watt appliance running for one hour. This is why electricity bills are calculated based on kWh consumption.

Operation Blue Star was a military operation conducted by the Indian Army in June 1984 at the Golden Temple complex in Amritsar. Its objective was to remove Sikh militants who had fortified the temple complex, not related to medical procedures or foreign military actions.

Work done is zero because centripetal force is always perpendicular to the displacement of the particle. Since work = F × d × cos(θ) and θ = 90° throughout circular motion, cos(90°) = 0, making work done zero regardless of the number of revolutions completed.

World AIDS Day is observed annually on December 1st to raise awareness about the AIDS pandemic caused by HIV spread. It was the first global health day established by the World Health Organization and has been recognized since 1988.

Amoeba performs intracellular digestion within food vacuoles, where enzymes break down food particles inside the cell. Unlike sponge (which uses intracellular digestion but is a simple organism), frog and fish rely on extracellular digestion in specialized digestive tracts.

An electric motor converts electrical energy into mechanical energy through electromagnetic principles. Current flowing through coils in a magnetic field creates torque, producing rotational motion. This is opposite to a generator, which converts mechanical energy into electrical energy.

The pulmonary artery in frogs (and all vertebrates) carries deoxygenated blood from the heart to the lungs for oxygenation. Unlike mammals, frogs have a three-chambered heart, but the pulmonary artery still carries impure (deoxygenated) blood.

Xerophytes are plants adapted to arid environments where water is scarce. They have developed specialized features like reduced leaves, thick cuticles, and extensive root systems to minimize water loss and maximize water uptake, making water their primary limiting factor.

A detergent is a cleaning agent that works by reducing surface tension and emulsifying oils, allowing water to wash away dirt and grease. Unlike soap (which is a specific type of detergent made from fats), detergents are synthetic compounds that work effectively in hard water.

Marsh gas is common name for methane (CH4), formed by anaerobic decomposition of organic matter in marshy areas. Ethyne (C2H2) is a different hydrocarbon, H2S is hydrogen sulfide with rotten egg odor, and CH3Cl is chloromethane.

 Bengali is the second language spoken after Hindi in India.

Heavy water or deuterium oxide has formula D2O, where D is deuterium (hydrogen-2 isotope with one neutron). D3O is incorrect stoichiometry, DO doesn't exist as stable molecule, and DO2 is not a valid formula.

The Indian national calendar (Saka Era) starts with Chaitra as the first month, typically corresponding to March-April. Megha, Ashadha, and Vaishakha are other months in the calendar but not the first.

For X-238 with atomic number 92, neutrons = mass number - atomic number = 238 - 92 = 146. This element is uranium (U-238). Option A (144) would give mass 236, B (148) gives 240, and C (242) is the mass number itself.

The SI unit of force is Newton (N). Joule is the SI unit of energy/work, Dyne is the CGS unit of force, and Torr is a unit of pressure.

Configuration 1s2 2s2 2p5 represents fluorine (7 valence electrons), one electron short of octet. It can either share an electron (covalent, as in F2) or gain one (ionic, forming F-). Option A is helium (noble gas), B is carbon (forms only covalent bonds), and D has a typo in notation.

The reaction H² + H² involves two deuterium nuclei fusing together, which is a nuclear fusion reaction. Fission splits a heavy nucleus, chain reaction is sustained fission, and thermal reaction is vague and non-specific.

In vacuum, all electromagnetic waves travel at speed c (3×10^8 m/s) regardless of frequency or wavelength. Different types have different frequencies and wavelengths but identical speed in vacuum.

Kinetic theory states that at a given temperature, all gas molecules have the same average kinetic energy (KE_avg = 3/2 kT). Lighter molecules move faster but their average energy equals heavier molecules' average energy. Speeds follow Maxwell-Boltzmann distribution.

Hygrometer measures humidity (water vapor content) in air. Calorimeter measures heat quantities, pyrometer measures high temperatures (especially in furnaces), and hydrometer measures liquid density/specific gravity.

G-15 (Group of Fifteen) is a summit level organization of developing countries established in 1989. It focuses on cooperation and providing input for other international organizations like WTO and IMF.

If winner gets 70% and wins by 200 votes: Winner - Loser = 200. Let total votes = T. Then 0.7T - 0.3T = 200, so 0.4T = 200, T = 500. Simple majority = 50% + 1 vote = 251 votes. (70% of 500 = 350 votes, 30% = 150 votes, difference = 200)

Initial mixture has 4L water (10% of 40L) and 36L milk. After adding x liters of water, total becomes (40+x) liters with (4+x) liters water. For water to be 20%: (4+x)/(40+x) = 0.20. Solving: 4+x = 8+0.2x, so 0.8x = 4, giving x = 5 litres.

A chemical formula represents the types of atoms in a compound and their relative proportions. For example, H2O shows hydrogen and oxygen atoms in a 2:1 ratio. Option D correctly identifies that formulas indicate different atom types present.

Let original price = 100, consumption = 100, so expenditure = 10000. After 25% price increase, new price = 125. To keep expenditure at 10000: 125 × new consumption = 10000. New consumption = 80, so reduction = 20%. Check: 1.25 × 0.8 = 1 (expenditure unchanged).

Tungsten is used for electric bulb filaments because it has an extremely high melting point (3422°C) and low vapor pressure at high temperatures. This allows it to withstand the intense heat of incandescence without rapidly evaporating or breaking.

Washing soda is the common name for sodium carbonate decahydrate (Na2CO3·10H2O). It's called "washing" soda because it's widely used as a water softener in laundry and cleaning products. Sodium carbonate alone (anhydrous) is soda ash.

Hydrogen (H2) is the lightest gas because it has the lowest molecular mass (2 g/mol) of all gases. All other gases like nitrogen (N2, 28 g/mol), ammonia (NH3, 17 g/mol), and carbon dioxide (CO2, 44 g/mol) are significantly heavier.

Above a fire, all three heat transfer mechanisms operate: conduction through the combustion zone, convection of hot gases rising upward, and thermal radiation emitted in all directions. The upward convection concentrates heat directly above, while radiation spreads outward, making it hottest directly above.

Acetylene (C2H2) is an alkyne with a triple bond. It decolorizes alkaline KMnO4 due to unsaturation and forms a white precipitate of silver acetylide with ammoniacal AgNO3. Methane (C2H6 is ethane, C2H4 is ethene, C2H is not a stable hydrocarbon) do not give both reactions.

The East India Company was founded in 1600 during the reign of Mughal Emperor Akbar (1556-1605). The Company received its royal charter from Queen Elizabeth I of England on December 31, 1600, establishing its trading presence in India.

International Literacy Day is observed annually on September 8th, as proclaimed by UNESCO in 1966. This day aims to highlight the importance of literacy for individuals and communities, and to promote global literacy efforts.