RRB Group D GK Questions 2026

Parallels of latitude are circles drawn parallel to the equator, and they grow shorter as one moves towards the poles, until a pole is a point with no length at all.

The correct answer is B, the Ten Degree Channel, which lies roughly along the parallel of ten degrees north and separates the Andaman group in the north from the Nicobar group in the south; Little Andaman lies to its north and Car Nicobar to its south.

The mainland of India extends from about 68 degrees 7 minutes east to about 97 degrees 25 minutes east, a longitudinal spread of roughly 29 degrees.

Carbon monoxide binds to haemoglobin far more strongly than oxygen does and forms carboxyhaemoglobin, so the blood cannot pick up oxygen even though breathing goes on; the gas is colourless and odourless, which makes it the more dangerous, and it is produced by the incomplete burning of fuel in closed…

Compressed natural gas is mainly methane, the simplest hydrocarbon, and biogas from a gobar gas plant is also mostly methane along with carbon dioxide, produced by the anaerobic decay of organic matter; methane is also called marsh gas because it bubbles up from waterlogged ground.

In the Haber process nitrogen from the air and hydrogen are combined under high pressure at a few hundred degrees Celsius over a catalyst of finely divided iron, and the ammonia so made is the starting point of nitrogenous fertilisers such as urea and of nitric acid.

Carbon dioxide reacts with lime water, a solution of calcium hydroxide, to form insoluble calcium carbonate, whose fine white particles make the liquid look milky; if more of the gas is passed the milkiness disappears as soluble calcium bicarbonate is formed, and that second step is often the harder half…

When an electric discharge is passed through neon at low pressure it glows a bright reddish orange, which is why the tubes of advertising signs and warning lights are filled with it, and the name neon sign has stuck to such tubes whatever gas they now contain.

Argon is chemically inert, so the hot tungsten filament does not react with it, and its presence also slows the evaporation of tungsten, which is why bulbs are filled with argon, sometimes mixed with nitrogen, instead of being left as a vacuum.

It is called laughing gas because it produces a feeling of elation when inhaled in small quantities, and it is used as a mild anaesthetic in dentistry and minor surgery and as the propellant in whipped cream; it is also a greenhouse gas.

Chlorine released from chlorofluorocarbons destroys ozone fastest where polar stratospheric clouds form in the extreme cold of winter, because those ice clouds hold the chlorine compounds that sunlight then breaks up; the thinning is therefore deepest over Antarctica, where it is called the ozone hole, and is seen over the…

Hydrogen has three isotopes: protium with one proton and no neutron, deuterium with one neutron, which gives heavy water, and tritium with two neutrons, which is radioactive and is used in fusion research and in luminous dials.

A metal more reactive than hydrogen displaces it from a dilute acid, so zinc with dilute sulphuric acid gives zinc sulphate and hydrogen gas, and this is the standard laboratory preparation of the gas; the test is that it burns with a pop.

Prokaryotic cells such as bacteria have no membrane-bound organelles, so they lack mitochondria. Prokaryotes have no true nucleus: their DNA lies in a region called the nucleoid, and they have no mitochondria, chloroplasts, endoplasmic reticulum or Golgi body.

Chalk, limestone and marble are all forms of calcium carbonate, CaCO₃. Chalk is a soft, porous rock built from the tiny shells of marine plankton.

Leucoplasts are colourless plastids that store food: starch, oils and proteins. Plastids are found only in plant cells and some algae, and they are of three main kinds.

Silver turns black in air because it reacts with sulphur compounds, mainly hydrogen sulphide, to form a thin black coating of silver sulphide (Ag₂S).

SONAR uses sound waves under water to find the distance and direction of objects. A SONAR set on a ship has a transmitter that sends out pulses of ultrasound and a detector that picks up their echo from the sea bed, a shoal of fish, a wreck or a submarine.

Tendons are made of tightly packed parallel bundles of collagen fibres, which give them great pulling strength. Collagen is the most abundant protein in the human body.

Its network of membrane tubes and sheets forms channels that carry materials, especially proteins, between parts of the cytoplasm and the nucleus.