QUIZ – 2020: INSIGHTS STATIC , 4 May 2021 – Science and Technology

Solution: a)

Noise-cancelling headphones (a smart wearable device) can be broken down into two main groups: passive and active.

Passive headphones simply reduce background noise by using insulating materials to prevent external noise from entering the ear.

Active headphones, on the other hand, are a little more complex.

Many active headphones have an external microphone that screens incoming sounds. When the microphone detects unwanted noise—such as a humming airplane engine—it sends a sound wave into the headphone speakers that is 180 degrees out of phase with the bothersome sound. Consequently, the two waves cancel each other out, resulting in silence. Unlike traditional earbuds or headphones, noise-cancelers require a rechargeable battery to send out the mirror waves.

Solution: b)

Solution: a)

Tuberculosis (TB) is caused by a bacterium called Mycobacterium tuberculosis.

Microbiological confirmation on sputum, chest x-ray screening etc. are some of the methods used to screen TB.

Solution: c)

Using NASA’s James Webb Space Telescope as a sort of time machine, researchers plan to investigate how new stars are born, with the help of a natural phenomenon called “gravitational lensing”.

• Gravitational lensing is an effect of Einstein’s theory of general relativity – simply put, mass bends light.
• The gravitational field of a massive object will extend far into space, and cause light rays passing close to that object (and thus through its gravitational field) to be bent and refocused somewhere else.
• The more massive the object, the stronger its gravitational field and hence the greater the bending of light rays – just like using denser materials to make optical lenses results in a greater amount of refraction.

Gravitational lensing is useful to cosmologists because it is directly sensitive to the amount and distribution of dark matter.

Lensing can help astronomers work out exactly how much dark matter there is in the Universe as a whole and also how it is distributed.

Lensing has also been used to help verify the existence of dark matter itself.

Solution: b)

India’s first indigenously developed high-temperature based Fuel Cell System. It is a 5.0 kW fuel cell system that generates power in a green manner.

It takes methanol as the input and produces heat and water as its bi-products

The developed fuel cells are based on High-Temperature Proton Exchange Membrane (HTPEM) technology.

• Developed under the Public-Private Partnership (PPP) model by the Council of Scientific and Industrial Research (CSIR) in partnership with Indian industries.
• Built under India’s flagship programme named ‘New Millennium Indian Technology Leadership Initiative (NMITLI)’.

Applications:

1. Suitable for distributed stationary power applications like; for small offices, commercial units, data centers etc.; where highly reliable power is essential with simultaneous requirement for air-conditioning.
2. It will also meet the requirement of efficient, clean and reliable backup power generator for telecom towers, remote locations and strategic applications as well.
3. Replace Diesel Generating (DG) sets and help reduce India’s dependence on crude oil.