RRB NTPC GK Questions 2026

A Mach number greater than 1 means the body is moving faster than sound in the surrounding medium. The Mach number is the ratio of a body's speed to the speed of sound in the medium around it, named after the Austrian physicist Ernst Mach.

The Mariana Trench lies in the western Pacific, east of the Mariana Islands and near Guam. It is the deepest known part of the world's oceans.

An object denser than the liquid sinks, and one less dense than the liquid floats. By Archimedes' principle, a body placed in a liquid feels an upward buoyant force equal to the weight of the liquid it displaces.

Milk is a colloid in which tiny droplets of fat are dispersed in water, so it is not uniform at the microscopic level and counts as a heterogeneous mixture.

The apple's gravitational potential energy first becomes kinetic energy as it falls, some is lost as heat to the air on the way, and at impact the rest goes into heating the ground and apple and into sound.

Diamond and graphite are allotropes of the same element, carbon, so their chemical properties are the same; only their physical properties differ.

In the electrolytic refining of copper, a solution of copper sulphate made acidic with a little dilute sulphuric acid carries the copper ions between the electrodes.

Two ammonium ions, each with a charge of +1, are needed to balance one carbonate ion with a charge of -2.

Putting a soft iron bar inside a solenoid makes the magnetic field much stronger, so the claim that the field stays the same is not correct.

It is a warm current that flows south along the east coast of Australia, carrying tropical water from the Coral Sea.

Magnesium combines with oxygen to form a new substance, magnesium oxide, so a chemical reaction takes place. When a magnesium ribbon is heated, it burns with a dazzling white flame and leaves a white powder: 2Mg + O₂ → 2MgO.

The nitride ion, N³⁻, carries a charge of minus three, so its valency is -3. Nitrogen has five electrons in its outer shell.

A telescope's objective must gather as much light as possible from a distant object and form a large image, so it is both wide and of long focal length.

At a fixed temperature, changing the pressure of an ideal gas does not change the speed of sound in it, so x and y are equal.

Abubshahar Wildlife Sanctuary lies in Sirsa district in the dry south-western corner of Haryana, in the belt through which the seasonal Ghaggar passes.

This is the law under which state governments declare national parks, wildlife sanctuaries, conservation reserves and community reserves, and under which species are listed in schedules for protection.

Kalesar in Yamunanagar district is the one place in Haryana with a genuine sal forest, a Shivalik type of dry deciduous forest mixed with khair, shisham, sain and semul, with chir pine on the higher slopes.

The crocodile breeding centre at Bhor Saidan lies in Kurukshetra district and breeds the marsh crocodile, the mugger. Kurukshetra also holds the Chhilchhila Wildlife Sanctuary, a wetland for migratory birds, and the deer and blackbuck enclosures at Pipli, so the district appears more than once in this chapter.

The blackbuck is the state animal of Haryana and survives in the open scrub and grassland of Sirsa, Hisar, Bhiwani and Rewari, where sanctuaries such as Abubshahar and Nahar protect it, helped in the south-west by the Bishnoi tradition of protecting wildlife.

Bir Shikargah Wildlife Sanctuary lies in the Shivalik tract of Panchkula district. The name itself explains its origin: a bir is an enclosed woodlot and shikargah means a hunting ground, so the area was a hunting preserve of the princely period that was later turned into a protected area.