Railway GK Questions 2026

Cyclohexane, C 6 H 12, has 6 C–C single bonds and 12 C–H single bonds, 18 single bonds in all and no double or triple bond.

Silver and copper are the two best conductors of heat among metals. Metals conduct heat because their free electrons carry energy quickly through the solid.

Velocity multiplied by time is displacement, so the area between a velocity-time graph and the time axis gives the displacement.

A bacterium is a prokaryote, so its DNA lies in an irregular region called the nucleoid, with no nuclear membrane around it.

Photo 51 is the X-ray diffraction photograph of DNA that revealed its helical shape. The picture was taken in May 1952 at King's College London by Rosalind Franklin and her student Raymond Gosling.

Twenty crests and twenty troughs make twenty complete waves in 0.1 second, so the frequency is 200 Hz and the wavelength is 330 ÷ 200 = 1.65 m. One complete wave, or one cycle, contains one crest and one trough (for sound, one compression and one rarefaction).

A freely falling object moves with a uniform acceleration, the acceleration due to gravity, g, about 9.8 m/s² near the Earth's surface.

A large part of the energy is lost at every trophic level, so after four or five links too little is left to support another level.

Lord Curzon's partition of Bengal came into effect on 16 October 1905, years before the other three events. Curzon announced the partition in July 1905, claiming it was for administrative convenience, but it was widely seen as a way to divide Hindus and Muslims and weaken Bengali nationalism.

Sodium reacts vigorously with cold water to form sodium hydroxide and hydrogen gas: 2Na + 2H₂O → 2NaOH + H₂.

Chlorofluorocarbons (CFCs) used in refrigerators, air conditioners, aerosol sprays and foams were the main cause of ozone depletion in the twentieth century.

Insulin is a protein (peptide) hormone made in the human body by the beta cells of the islets of Langerhans in the pancreas.

After fertilisation, each ovule grows into a seed, and the ovary that holds the ovules grows into the fruit. In flowering plants, a pollen tube carries two male gametes to the ovule.

Gold is a noble metal at the bottom of the reactivity series, so it does not react with oxygen, water or ordinary acids.

Biogas is mostly methane, usually about 50 to 75 percent, and it is the methane that burns with a clean blue flame and no smoke.

In photosynthesis, green plants take carbon dioxide from the air and combine it with water, using sunlight, to make carbohydrates such as glucose.

On 13 April 1919 troops fired without any warning on an unarmed crowd in Jallianwala Bagh, Amritsar, on the orders of Brigadier-General Reginald Dyer.

The breakdown of glucose into pyruvate, called glycolysis, takes place in the cytoplasm (cytosol) of the cell. Glycolysis is the first step of respiration in almost every living cell.

Burning coal, petrol and diesel releases oxides of sulphur and nitrogen (and carbon), which dissolve in rain water to form acids.

When blood glucose is more than the body needs, the hormone insulin helps convert it into glycogen, which is stored mainly in the liver and the muscles.