Science & Technology GK Questions with Answers – Page 7

A BEV carries no engine at all; it runs entirely on a traction battery that is charged from an external electricity supply, and it has no tailpipe emissions.

This is a glucose analogue in which fluorine-18 replaces a hydroxyl group.

It regulates the use of pre-natal diagnostic techniques, requires every ultrasound clinic to be registered and to keep records, and prohibits sex selection before or after conception as well as the communication of the sex of the foetus to anyone.

Gadolinium is a rare earth element whose ion is strongly paramagnetic, so it shortens the relaxation time of nearby hydrogen nuclei and brightens the tissue it reaches.

Hounsfield, an engineer at EMI in Britain, built the first clinical CT scanner, and Cormack, a physicist, had independently worked out the mathematics of reconstructing a cross-section from measurements taken along many directions.

When sound is reflected from a moving target, the frequency of the echo is shifted: higher when the blood is moving towards the probe and lower when it is moving away.

Certain crystals develop a voltage across their faces when they are mechanically squeezed, and conversely change shape when a voltage is applied.

The tesla is the SI unit of magnetic flux density, and clinical MRI scanners commonly work at one and a half or three tesla, produced by a superconducting coil kept cold by liquid helium.

A single proton, the nucleus of ordinary hydrogen, has a spin and therefore a magnetic moment, and hydrogen is by far the most abundant such nucleus in the body because the body is largely water and fat.

The cutoff or minimum wavelength of the continuous X-ray spectrum arises when an electron gives up its entire kinetic energy in a single collision with the target.

The Hounsfield unit, named after Godfrey Hounsfield, expresses how strongly a small volume of tissue attenuates X-rays, on a scale fixed by definition at zero for water and minus one thousand for air.

MRI works by placing the hydrogen nuclei of the body in a strong static magnetic field and disturbing them with radiofrequency pulses, which lie in the harmless low-energy part of the electromagnetic spectrum.

Working with a discharge tube at the University of Wurzburg in November 1895, Roentgen noticed that a screen coated with a fluorescent salt glowed even when the tube was covered, and he traced the effect to an unknown penetrating radiation that he called X-radiation.

LiFi (Light Fidelity) sends data wirelessly by switching LED light on and off far too fast for the eye to notice, and it can be many times faster than WiFi.

Himansh was established in 2016 in the Spiti area of Himachal Pradesh, in the upper reaches of the Chandra basin, so that scientists can measure the mass balance, melt and movement of Himalayan glaciers through the year instead of only on short visits.

India was the first country to be granted Pioneer Investor status by the International Seabed Authority, in 1987, and holds an exploration area of seventy-five thousand square kilometres in the Central Indian Ocean Basin for polymetallic nodules, which are lumps on the deep seabed rich in manganese, nickel, cobalt and…

This autonomous institute of the Ministry of Earth Sciences designs and builds India's ocean engineering hardware, from desalination plants and moored buoys to deep-sea mining systems, and it is developing Matsya-6000 along with the systems that will support the dives.

Matsya-6000 takes its name from the design depth of six thousand metres and is built to carry a crew of three inside a titanium personnel sphere.

The Cabinet approved the Deep Ocean Mission in June 2021 with this ministry as the implementing agency and an estimated cost of about 4,077 crore rupees spread over five years in phases.

The Antarctic Treaty was signed on 1 December 1959 by twelve nations that had been active in the continent during the International Geophysical Year, and it came into force in 1961.