SSC GK Questions 2026

El Nino, Spanish for the child, is the warm surface water that appears off the coast of Peru and Ecuador around Christmas in some years, replacing the normally cold Peru or Humboldt current.

It is a warm current of the Indian Ocean that flows southward along the eastern coast of southern Africa, carrying tropical water towards the Cape before most of it turns back into the Indian Ocean.

The sensation of a sound persists in the human brain for roughly one tenth of a second, so a reflected sound must arrive at least that much after the original to be heard as a separate echo.

SONAR stands for Sound Navigation and Ranging. A transmitter on the ship sends short ultrasonic pulses into the water, the pulses are reflected from the sea bed, a submarine, an iceberg or a shoal of fish, and a detector records the returning echo.

Sound travels fastest in solids because their particles are packed closely and are strongly bound, so a disturbance is passed on to the next particle almost at once.

This is the band of frequencies to which a healthy human ear responds, and the upper limit falls with age.

A vacuum contains no particles, and a mechanical wave such as sound can travel only by making particles vibrate and hand the disturbance on to their neighbours.

In a sound wave the particles of the medium vibrate back and forth along the same line in which the wave is travelling, producing regions where they crowd together, called compressions, and regions where they spread apart, called rarefactions.

The flash and the clap are produced at the same instant by the same discharge.

Amplitude is the maximum displacement of a particle of the medium from its rest position, and the energy carried by a wave increases with the square of the amplitude.

Convert the units first: 1 kilohertz is 1000 hertz and 50 centimetres is 0.5 metre. The speed is frequency multiplied by wavelength, that is 1000 multiplied by 0.5, which gives 500 metres per second.

Pitch is the characteristic of a sound by which the brain judges it as shrill or flat, and it is decided by the frequency of the wave.

The speed of a wave is the product of its frequency and its wavelength, so the speed here is 50 hertz multiplied by 4 metres, that is 200 metres per second.

The Minamata Convention on Mercury was adopted in 2013 and entered into force in 2017. It controls the supply and trade of mercury, restricts its use in products such as batteries, switches and certain measuring devices, and regulates emissions from coal burning and from small-scale gold mining.

The Cartagena Protocol on Biosafety, adopted in 2000, governs the safe handling, transport and use of living modified organisms produced by modern biotechnology.

The United Nations Conference on the Human Environment met at Stockholm in June 1972 and was the first global gathering to treat the environment as a subject of international policy.

The Basel Convention was adopted in 1989 after public anger at the export of toxic waste from industrialised countries to poorer ones, and it requires prior informed consent from the importing state before such a shipment may be made.

The Paris Agreement was adopted at the twenty-first Conference of the Parties in 2015 and entered into force in 2016.

The Kyoto Protocol was adopted at the third Conference of the Parties to the framework convention on climate change, held at Kyoto in Japan in 1997.

It was agreed at Washington in 1973 and came into force in 1975.