Defence GK Questions 2026

Cerium oxide (CeO2) strongly absorbs ultraviolet rays while letting visible light through, so it is added to glass to make it UV-protective.

Congress was represented by Jawaharlal Nehru and Maulana Abul Kalam Azad, its president, not by Sardar Patel. With Japan advancing in South-East Asia, the British War Cabinet sent Sir Stafford Cripps to India in March 1942, after he had persuaded it to accept a draft declaration.

Methanol (CH3OH) is called wood spirit or wood alcohol because it was first obtained by the destructive distillation of wood.

Where oil meets water, the unequal pull of their molecules sets up a surface (interfacial) tension that keeps the two liquids as separate layers.

Violet light has the shortest wavelength among the visible colours, so the medium bends it the most. The splitting of white light into its colours is called dispersion.

Mitochondria carry their own circular DNA and their own ribosomes, so they can make some of their own proteins. Mitochondria are the sites of aerobic respiration, where ATP is produced, which is why they are called the powerhouse of the cell.

Photosynthesis absorbs energy from sunlight to build glucose, so it is an endothermic process. An endothermic process takes in heat or light from its surroundings, while an exothermic one gives energy out.

In this 1992 case, also called the Mandal case, the Supreme Court held that the creamy layer must be kept out of OBC reservation.

Springs appear where groundwater meets a barrier or a surface outlet, which happens in jointed rocks, karst areas and tilted strata, but not commonly in dry regions.

The de Broglie wavelength depends only on momentum, so equal wavelengths mean equal momenta. In 1924 Louis de Broglie proposed that every moving particle has a wave linked to it, with wavelength λ = h/p, where h is Planck's constant and p is the linear momentum.

The product forms a coating that shuts the acid out. Calcium reacts with dilute sulphuric acid to give calcium sulphate and hydrogen gas: Ca + H2SO4 gives CaSO4 + H2.

Kautilya's daily time-table for the king does not include moving through the town in disguise; he learns about his people through spies instead.

The atomic number (Z) is defined as the number of protons in the nucleus of an atom. Every atom of an element has the same number of protons, so the atomic number identifies the element: hydrogen has 1, carbon 6 and oxygen 8.

India's net zero target announced at COP-26 is the year 2070, not 2047. At COP-26 in Glasgow in November 2021, Prime Minister Narendra Modi announced five commitments called the Panchamrit (five nectar elements).

The United Nations Sasakawa Award for Disaster Risk Reduction honours people and institutions that work to reduce the risk of disasters.

X-rays are electromagnetic waves with no electric charge, so electric fields cannot deflect them. X-rays were discovered by Wilhelm Röntgen in 1895, who won the first Nobel Prize in Physics in 1901 for it.

Leh lies in the rain shadow of the Great Himalaya and gets only about 100 mm of precipitation a year, making it one of the driest places in India.

A. V. Thakkar, known as Thakkar Bapa, founded the Bhil Seva Mandal in 1922 to work for the Bhil tribals of the Panchmahal district of Gujarat.

Energy shrinks sharply at each step of a food chain, so after a few levels too little is left to support another level of consumers.

This is a double displacement (precipitation) reaction, in which no element gains oxygen or loses electrons. When the two solutions are mixed, the ions swap partners: BaCl2 + Na2SO4 → BaSO4 + 2NaCl.