science & technology Online Quiz - 151

RAW (Research and Analysis Wing) is India's external intelligence agency, created in 1968 after the India-China and India-Pakistan wars. It handles foreign intelligence, similar to how the CIA handles external intelligence for the US. The Intelligence Bureau (IB) handles domestic intelligence, Military Intelligence is within the armed forces, and CBI is a criminal investigation agency.

India signed an MoU with Russia to jointly develop the Fifth Generation Fighter Aircraft (FGFA), based on Russia's Su-57 platform. This partnership aimed to develop an advanced multi-role stealth fighter. Israel, France, and the USA were not part of this specific 5th gen fighter project.

MPFI stands for Multi Point Fuel Injection, a system where fuel is injected into each cylinder's intake port individually. This provides better fuel efficiency and emissions control compared to single-point carburetor systems. The other options are not the correct expansion.

CRDe stands for Common Rail Diesel engine, a fuel injection technology used in modern diesel engines. The 'common rail' refers to the single fuel line that supplies all cylinders with high-pressure fuel. This system improves efficiency and reduces emissions compared to traditional diesel injection.

This question asks which author-work pairing is INCORRECT. Vishwas Patil is famous for 'Zandi' (about the 1857 revolt), not 'Zombi'. The other three pairings are all correct Marathi literary works by their respective authors.

Milk contains lactic acid, which is produced when bacteria ferment lactose (milk sugar). Fresh milk contains very little lactic acid, but it increases as milk sours or ferments into products like yogurt. Oxalic acid is found in spinach, citric acid in citrus fruits, and boric acid is not naturally found in food.

Chlorine gas (Cl2) is greenish-yellow in color, which gives it its name from the Greek 'chloros' meaning greenish-yellow. Hydrogen is colorless, Neon is reddish-orange in discharge tubes but colorless as a gas, and Krypton is colorless.

In the tertiary structure of proteins (including keratin in hair), disulfide bonds form between the sulfur atoms in cysteine amino acid R groups. These covalent bonds provide structural stability and are responsible for hair's strength. Carbon-carbon bonds don't specifically link R groups, hydroxide is not a bond type, and dihydride is not a relevant term.

Ammonia (NH3) is a basic gas widely used in fertilizer production, including urea manufacture. The Haber process combines nitrogen and hydrogen to produce ammonia. Hydrogen is neutral, nitrogen is inert, and chlorine is acidic - none are basic or used in urea production.

Carbonic acid (H2CO3) is responsible for carbonation in soft drinks. When CO2 dissolves in water under pressure, it forms carbonic acid, which creates the 'fizz' and tingling sensation. Citric acid adds flavor but not fizz, acetic acid is in vinegar, and oxalic acid is toxic.

Pencil 'lead' is actually graphite, a form of carbon. The misconception comes from graphite historically being called 'black lead.' Plastic is used in pencil casings, carbon black is a pigment, and lead is toxic and never used in pencils.

Sulfuric acid (H2SO4) is historically known as 'Oil of Vitriol.' The term 'vitriol' refers to sulfate salts, and sulfuric acid was the most important. Hydrochloric acid is 'muriatic acid,' and neither hydroiodic nor nitric acid have this common name.

Vinegar is very dilute acetic acid (typically 4-8% acetic acid in water). Citric acid is in citrus fruits, carbonic acid is in carbonated water, and phosphoric acid is in some dark sodas but not vinegar.

Gold is often found in the pure (native) state because it is unreactive and doesn't easily oxidize or form compounds. Magnesium, Silver, and Iron are reactive and are typically found as ores or compounds that need refining.

Sulfuric acid is used in lead-acid car batteries as the electrolyte. When the battery discharges, it reacts with lead plates to form lead sulfate. Hydrochloric and nitric acids are too corrosive and reactive for this use, and phosphoric acid is used in some rust removal but not standard car batteries.

Potassium hydroxide (KOH) is commonly known as 'Caustic Potash', just as sodium hydroxide (NaOH) is called 'Caustic Soda'. Both are strong alkalis used in various industrial applications. Calcium hydroxide is slaked lime, magnesium hydroxide is milk of magnesia.

Tata Indica was the first fully designed and manufactured passenger car in India, launched in 1998 by Tata Motors. The Maruti 800 was based on a Suzuki design, Hindustan Ambassador was based on the Morris Oxford, and Premier Padmini was based on the Fiat 124. The Indica was an indigenous design project.

Convex lenses (converging lenses) are used to correct long-sightedness (hypermetropia or hyperopia). In this condition, the eyeball is too short or the cornea has insufficient curvature, causing light to focus behind the retina instead of on it. Convex lenses converge light rays before they enter the eye, moving the focal point forward onto the retina. Concave lenses are used for short-sightedness (myopia), while mirrors (concave or convex) are not used for vision correction.