Science and Technology MCQ Set 49
Showing question 241 to 245 of total 301 MCQs
MCQ Set: 49
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Question No: 241
Which summer fruit has IIT Roorkee science team used to make solar cells?
- Jamun
- Mango
- Banana
- Melon
Answer and Explanation
Answer: A
Explanation
Scientists at IIT Roorkee have used the juicy, delectable Indian summer fruit Jamun to create inexpensive and more efficient solar cells.
Researchers used naturally occurring pigment found in jamun as an inexpensive photosensitiser for Dye Sensitised Solar Cells (DSSCs) or Gratzel cells.
Gratzel cells are thin film solar cells.
These composed of a porous layer of titanium dioxide (TiO2) coated photoanode.
This is a layer of dye molecules that absorbs sunlight.
Also used were an electrolyte for regenerating the dye, and a cathode.
These components form an in between-like structure with the dye molecule or photosensitizer playing a pivotal role through its ability to absorb visible light.
The dark colour of jamun and abundance of jamun trees in IIT campus clicked the idea that it might be useful as a dye in the typical Dye Sensitised Solar Cells (DSSC).
Researchers extracted dyes from jamun using ethanol. They also used fresh plums and black currant, along with mixed berry juices which contain pigments that give characteristic colour to jamun.
The mixture was then centrifuged and decanted. The extracted coloured pigment called anthocyanin was used as a sensitiser.
Natural pigments are way economical in comparison to regular Ruthenium-based pigments and scientists are optimising to improve the efficiency. The increasing pressure on fossil fuels and concern of global warming has inspired continuous search for alternate energy,
India aims to deliver on the country’s pledge to build up a 40 per cent share of non-fossil fuel capacity in the power sector by 2030, researchers said.
There is a large social need for renewable energy especially solar energy. The lab is actively engaged in low cost high efficiency solar cells production.
The simplicity and cost effectiveness of the overall fabrication process, widespread availability of fruits and juices, and ease of extraction of anthocyanin dyes render them novel and inexpensive candidates for solar cells application.
Jamun: Know More
Syzygium cumini, known as jambul, jambolan, jamblang or jamun, is an evergreen tropical tree.
It is in the flowering plant family Myrtaceae.
Syzygium cumini is native to the Indian Subcontinent and adjoining regions of Southeast Asia.
The species ranges across India, Bangladesh, Pakistan, Nepal, Sri Lanka, Malaysia, the Philippines, and Indonesia.
USDA grew the first jamun tree in the US in Florida.
Question No: 242
In a novel approach to TB drug discovery, CSIR scientists have done which of the following?
- Speeded up drug discovery by finding potential non toxic drug targets
- Reduced the cost of drug discovery by lowering chances of failure
- Both a and b
- Neither a nor b
Answer and Explanation
Answer: C
Explanation
In a completely different approach to drug discovery, Delhi’s CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB) has used a combination of approaches to predict potential drug targets in Mycobacterium tuberculosis.
This is a TB-causing bacteria.
The novel method not only helps in speeding up drug discovery by finding potential, non-toxic drug targets but will also cost far less by reducing the chances of failure.
The results were published in the journal Scientific Reports.
Conventionally, drug discovery was never looked at from a systems biology point of view.
The approach the scientists used was rather unconventional, aimed at finding targets first based on evolutionary conservation principle in an organism,
Based on a previous study that used the Systems Biology Spindle Map (SBSM) approach, the team was able to identify 890 novel, non-toxic gene drug targets.
Using computational approaches, the potential drug targets were reduced to 116 essential genes; these 116 genes are so vital that any inhibition would kill the bacteria.
In order to identify drug targets with the least likelihood of side effects, the 116 essential genes were compared with the human genome and human microbiome at the sequence level to identify genes that did not have any similarity (homology) with human genome sequences.
Of the 116 genes, 104 were found to have no similarity with the human genome sequences, meaning any drug developed targeting these 104 genes will only target the TB bacteria and not cause any harm to human cells.
The potential drug targets were further shortlisted to 33 genes.
The presence or absence of mutations in any of the 33 genes was evaluated using the Genome-wide Mycobacterium tuberculosis Variation (GMTV) database.
The genes which are essential for bacteria never undergo any mutations as that would be lethal for their survival.
The crystal structure, which is essential for carrying out drug discovery process, was available for 15 of the 33 targets.
Once scientists have the targets and have structures of these targets then can tailor-make molecules to inhibit even MDR-TB and XDR-TB,.
The team has already carried out druggability assessment (to find out if the targets have certain properties for a drug to bind to receptors) for all the 33 gene targets.
Most of the 33 genes were found to be highly druggable validating the study.
There is a need for drug discovery to move from Wright brothers’ era of trial and error method. The trial and error approach is slow and too expensive.
All the genes, targets and even ligands will be in open source so anyone can develop new drug molecules.
Question No: 243
Scientists have found vast _______ on the surface of Antarctica ice sheets accelerating rise in sea level?
- Lakes
- Streams
- Both a and b
- None of the above
Answer and Explanation
Answer: C
Explanation
Scientists have found that vast lakes and streams are widespread on the surface of Antarctica's ice sheets.
This may accelerate its contribution to the rise in sea-level as it moves surface water across its ice sheets onto ice shelves.
Researchers used aerial photography and satellite imagery to find that melt-water moves vast distances across the surface of the ice sheets onto ice shelves.
Huge lakes have been forming on the surface of Antarctica since at least the 1940s and extensive networks of streams have been draining water onto vulnerable ice shelves that are prone to collapse.
Scientists previously believed that the drainage of surface water, known as melt-water, was a rarity in Antarctica.
Ice shelves, which are floating parts of ice sheets, are prone to collapse when water flows into their cracks and crevasses.
If melted completely, Antarctica's ice sheets contain enough water to raise global sea levels by around 58 metres.
Question No: 244
What is the name of the SAARC satellite to be launched on May 5, 2017?
- South Asia Satellite
- South Asian Association Satellite
- South East Asia satellite
- SAARC satellite
Answer and Explanation
Answer: A
Explanation
The South Asia Satellite will be launched on May 5, India’s “priceless gift” to its neighbours as part of the 'sabka sath, sabka vikas' concept.
Seven out of eight SAARC countries are a part of the project which Pakistan refused to join as it did not want the "gift" from India.
The concept of 'sabka sath, sabka vikas' is not confined to India but is relevant globally too, especially in the context of the neighbourhood.
The benefits of this satellite will go a long way in meeting the developmental needs of the countries participating in this project.
This is an appropriate example of India's commitment towards South Asia. The satellite of South Asia will help in the overall development of the entire region
The benefits will be in the partner countries in areas of mapping of natural resources, tele-medicine, education, IT connectivity and people-to-people links, he said.
These countries, besides India, are Nepal, Bangladesh, Bhutan, Sri Lanka, Maldives and Afghanistan.
Modi had made a unilateral proposal of India launching the satellite whose data would be shared with the eight SAARC countries for their development.
Initially, it was to be named as ‘SAARC Satellite’ but its name was changed to South Asia Satellite after Pakistan refused to join the project.
Basically, the satellite is meant for providing communication and disaster support, connectivity among the countries of South Asia region.
It will provide a significant capability to each of the participating countries in terms of DTH, certain VSAT capacity plus linking among the states for both disaster information transfer and also in terms of library type of things.
Question No: 245
How many communication satellites is SRO going to launch by the end of 2017?
- 4
- 5
- 6
- 7
Answer and Explanation
Answer: B
Explanation
The Indian Space Research Organisation (ISRO) is going to launch five communication satellites by the end of 2017.
The main aim behind the launch is to improve the communication system within the country.
The specific use of the satellites would be to improve the number of available transponders for communications.
The move is expected to significantly enhance India’s communication capability.
An overview of the number of satellites launched by the space organisation and the purpose of each satellite in the areas of disaster management, weather forecasting, space exploration, education, agriculture and geo-spatial applications was also provided.
India is the only country to achieve the feat of having a large number of satellites.
ISRO along with the government has made it mandatory for all aircrafts to have a GPS-aided Geo Augmented Navigation (GAGAN) system by 2019 to ensure safety and precision landing.
Apart from this, ISRO plans to make an inventory and site management plan for 4000 heritage sites in India.
The organisation also helped India break the record for launching most satellites from a single rocket by launching 104 satellites in one go in February 2017.
GAGAN: Know More
The GPS Aided GEO Augmented Navigation (GAGAN) is an implementation of a regional satellite-based augmentation system (SBAS) by the Indian government.
It is a system to improve the accuracy of a GNSS receiver by providing reference signals.
Project cost?: ?INR 7.74 billion (US$120 million)
Fully operational by?: ?2013-14
Launched?: ?2011-2012