NDA GK Questions 2026

TRAI was set up under the Telecom Regulatory Authority of India Act, 1997, to regulate telecom services, fix tariffs and protect the interests of consumers once private operators entered the field.

The first mobile telephone call in India was made on 31 July 1995 between Kolkata and New Delhi, a year after the National Telecom Policy of 1994 opened mobile services to private operators.

The three categories actually defined are given in the other options.

Under IMT-2020 the peak downlink data rate for 5G is set at 20 gigabits a second, with 10 gigabits a second in the uplink; these are laboratory peaks under ideal conditions, not the speed a subscriber sees, and the separate target for the user experienced rate is 100 megabits a…

LTE is the radio technology through which 4G was delivered; the name was chosen because it was presented as the long-term evolution of the earlier 3G standards rather than a break with them.

The International Telecommunication Union names each generation of mobile telephony by a standard family, and 5G is IMT-2020, whose requirements include a peak downlink rate of 20 Gbps, a user experienced rate of 100 Mbps, one millisecond of air interface latency and a million connected devices in a square kilometre.

Commercial 5G services began in India on 1 October 2022, when they were launched at the India Mobile Congress in New Delhi, following the spectrum auction held earlier that year in the 600 MHz, 700 MHz, 3300 MHz and 26 GHz bands among others.

A Geiger-Muller counter contains a gas-filled tube in which an entering ray ionises the gas and sets off a pulse of current, so each pulse counts one particle; a film badge worn by a worker records the total dose instead.

Iodine-131 has a half-life of roughly eight days, which is why the danger from it after an accident is intense but short-lived, and why potassium iodide tablets are distributed at once so that the thyroid gland is saturated with ordinary iodine and absorbs less of the radioactive form.

Reactor number four of the Chernobyl plant, in Ukraine in the then Soviet Union, exploded on 26 April 1986 and scattered radioactive iodine, caesium and strontium over a wide area of Europe.

The becquerel, symbol Bq, is the SI unit of activity and equals one disintegration per second.

Strontium lies just below calcium in the same group of the periodic table and behaves chemically like it, so strontium-90 taken in through milk, water or food is deposited in bone and in teeth in place of calcium.

A cooling tower releases the heat of used cooling water to the atmosphere by evaporation or by air flow, so that the water leaving the plant is close to the temperature of the receiving river or lake.

Thermal and nuclear power stations draw large volumes of water to condense steam and return it several degrees warmer, which makes them the single largest source of waste heat in rivers, lakes and coastal waters.

The solubility of a gas in water decreases as the temperature of the water rises, so hot water discharged from a power station holds less dissolved oxygen.

The Rules define a silence zone as the area up to 100 metres around a hospital, an educational institution or a court, and such an area has to be declared by the competent authority.

The Rules of 2000 lay down 55 decibel as the day-time limit and 45 decibel as the night-time limit for a residential area.

The Noise Pollution (Regulation and Control) Rules were notified in the year 2000 and they were framed under the Environment (Protection) Act, 1986.

The decibel, written dB, is the unit in which the intensity level of sound is expressed, and it is named after Alexander Graham Bell.

India touches China through Ladakh, Himachal Pradesh, Uttarakhand, Sikkim and Arunachal Pradesh, and Nagaland is not on that boundary; its international border is with Myanmar.