Railway GK Questions 2026

A magnesium atom sits at the centre of every chlorophyll molecule, so a plant cannot make chlorophyll without it. Chlorophyll is built around a ring-shaped structure called a porphyrin, with a single magnesium ion held at its centre.

A carbonate reacts with an acid at room temperature to give carbon dioxide, and only carbon dioxide turns limewater milky.

The body's weight stays the same, but standing puts it on the small area of the feet, so the pressure is greater.

Silver is the best conductor, nichrome is an alloy with high resistivity, and glass is an insulator with enormous resistivity.

During a hard sprint the muscles run short of oxygen and switch to anaerobic respiration, which leaves lactic acid behind.

Gravitational force varies inversely as the square of the distance, so halving the distance makes the force 2 × 2 = 4 times larger.

Plants need magnesium in fairly large amounts, so it is a macronutrient, not a micronutrient. Plant nutrients are grouped by how much of them a plant needs.

Lactase breaks down lactose, the sugar in milk, so a person who still makes enough of it can digest milk at any age.

A bacterium is a living cell filled with cytoplasm, while a virus is only genetic material inside a protein coat.

Animal cells are bounded only by a flexible cell membrane; a rigid cell wall is found in plants, fungi and bacteria.

A liquid boils when its vapour pressure equals the pressure above it, so less outside pressure means boiling starts at a lower temperature.

All three subjects sit in the list named against them in the Seventh Schedule. The Seventh Schedule, read with Article 246, divides law-making powers into three lists.

Magnesium burns in air with a dazzling white flame, which is why it goes into fireworks, sparklers and flares. When magnesium ribbon is heated it reacts with oxygen to form white magnesium oxide (2Mg + O2 → 2MgO), giving out intense heat and brilliant white light, including ultraviolet.

A short-sighted (myopic) person sees near things clearly but distant things blurred, and a concave lens corrects it.

A compound microscope uses two convex lenses, and its magnification depends on the tube length. The objective is a convex lens of very short focal length that forms a real, enlarged image of the specimen.

The third law does not make one force the cause and the other the effect; action and reaction arise together, at the same instant.

A real, inverted image of the same size forms only when the object sits at twice the focal length of a convex lens, so 2f = 10 cm and f = 5 cm.

Light inside the fibre strikes the boundary at more than the critical angle, so it is reflected back again and again instead of escaping.

A speed radar measures how much the frequency of its reflected wave changes, and that change depends on the speed of the vehicle.

Both kinds of radiation carry energy that food absorbs as heat, and both are used in everyday kitchens. Infrared radiation is the heat radiation given out by hot bodies: a grill, a toaster, an oven element or glowing coals cook the surface of food mainly by infrared rays.