Defence GK Questions 2026

She was the daughter of Mirza Ghiyas Beg, whom Jahangir honoured with the title Itmad-ud-Daula, and after her marriage to the emperor in 1611 she was styled Nur Mahal, light of the palace, and then Nur Jahan, light of the world; coins were struck in her name along with the…

The ambition announced by the title matched his record: the conquest of Gujarat, Ranthambore, Chittor, Malwa and the Deccan campaigns of Malik Kafur, besides the market control regulations and the first systematic measurement of land for revenue.

Ruling from 1266 to 1287 over a sultanate weakened by factions, he raised the throne above the nobility by claiming Zil-i-Ilahi and Niabat-i-Khudai, deputy of God, and by making courtiers perform sijda, prostration, and paibos, kissing the feet.

The founder of the Slave or Mamluk dynasty was called Lakh Baksh for his lavish charity, and he began the Qutb Minar at Delhi and the Adhai Din ka Jhonpra at Ajmer.

He conquered the territories of the Western Kshatrapas in Gujarat and Malwa, which gave the Guptas access to the western ports, and he used the titles Vikramaditya, Simhavikrama and Devashri; the Chinese pilgrim Fa-hien visited India in his reign.

The Nasik cave inscription issued by his mother Gautami Balashri praises the Satavahana ruler as Trisamudratoyapitavahana and as Ekabrahmana, and credits him with destroying the Shakas, Yavanas and Pahlavas.

The Allahabad pillar inscription, a prashasti composed by his court poet Harisena, lists his campaigns in the Ganga valley, the Deccan and the frontier states and calls him Sarvarajochchetta; the same inscription gives him Kaviraja for his learning, and his coins show him playing the veena.

Ashoka edicts almost never use his personal name; they speak of Devanampiya Piyadassi, the beloved of the gods and of pleasing appearance.

A light year is the distance that light travels in vacuum in one year at about 3 into 10 to the power 8 metres per second, which works out to roughly 9.46 into 10 to the power 12 kilometres; astronomers use it because distances between stars are awkward to write…

Visible light runs from about 400 nanometres at the violet end to about 700 nanometres at the red end, so violet has the shortest wavelength, the highest frequency and the greatest energy of the seven colours remembered as VIBGYOR.

Maxwell showed that this speed is fixed by the electric permittivity and magnetic permeability of free space, and its agreement with the measured speed of light was the proof that light is an electromagnetic wave; every band of the spectrum shares the same value in vacuum.

Ozone in the stratosphere absorbs most of the harmful shorter ultraviolet, and that is why the thinning of the layer by chlorofluorocarbons raises the risk of skin cancer, cataract and damage to crops; the small part of ultraviolet that does reach the surface makes vitamin D in human skin.

A remote control carries a small light emitting diode that sends coded pulses of near infrared, which a sensor in the set decodes; the radiation is invisible, harmless at that power and does not pass through walls, so remotes in neighbouring rooms do not interfere.

In 1800 he passed sunlight through a prism and moved a thermometer across the coloured band; the reading went on rising past the red end, which showed the presence of an invisible heating radiation now called infrared.

In 1895 he noticed that a screen coated with a fluorescent salt glowed when a discharge tube was working nearby even though the tube was covered, and he called the unknown radiation X-rays; he received the first Nobel Prize in Physics in 1901 for the discovery.

The spectrum in order of rising wavelength runs gamma rays, X-rays, ultraviolet, visible light, infrared, microwaves and radio waves, and the option follows that sequence with the visible and microwave bands left out.

They have the shortest wavelength of the spectrum and therefore the highest frequency and energy, and being uncharged and very energetic they pass through several centimetres of lead, which is why thick shielding is needed in radiotherapy rooms.

Their wavelength runs from about a tenth of a metre up to many kilometres, which makes them the longest and therefore the lowest in frequency and energy of the whole spectrum; they are used in broadcasting, mobile telephony and radio astronomy.

In an electromagnetic wave the electric field, the magnetic field and the direction of propagation are mutually perpendicular, and because the wave is made of fields and not of vibrating particles it needs no medium, which is how sunlight crosses empty space while sound cannot.

In 1887 he used a spark gap oscillator to generate waves and a loop with a gap to detect them, and he measured their wavelength and showed that they behaved like light in reflection and refraction, which confirmed the theory.