Question Discussion & Solution

i) Point B is 3m North of point A.

ii) Point C is 3m West of point B.

iii) Point D is 5m South of point C.

iv) Point E is 7m East of point D.

Drawing the Diagram as per the given information:

Thus we can se direction of E is South-East with reference to point B.

Hence, the correct is "South-East".

The correct answer is Leeuwenhoek.

Key Points

Additional Information

• Penicillin:
  • Penicillin is one of the first and still one of the most widely used antibiotic agents, derived from the Penicillium mold.
  • In 1928 Scottish bacteriologist Alexander Fleming first observed that colonies of the bacterium Staphylococcus aureus failed to grow in those areas of a culture that had been accidentally contaminated by the green mold Penicillium notatum.
  • He isolated the mold, grew it in a fluid medium, and found that it produced a substance capable of killing many of the common bacteria that infect humans.
  • Australian pathologist Howard Florey and British biochemist Ernst Boris Chain isolated and purified penicillin in the late 1930s, and by 1941 an injectable form of the drug was available for therapeutic use.
• Microscope:
  • Microscope is an instrument that produces enlarged images of small objects, allowing the observer an exceedingly close view of minute structures at a scale convenient for examination and analysis.
  • Although optical microscopes are the subject of this article, an image may also be enlarged by many other waveforms, including acoustic, X-ray, or electron beam, and be received by direct or digital imaging or by a combination of these methods.
  • The microscope may provide a dynamic image (as with conventional optical instruments) or one that is static (as with conventional scanning electron microscopes).
• Reverse transcriptase:
  • Reverse transcriptase also called RNA-directed DNA polymerase, an enzyme encoded from the genetic material of retroviruses that catalyzes the transcription of retrovirus RNA (ribonucleic acid) into DNA (deoxyribonucleic acid).
  • This catalyzed transcription is the reverse process of normal cellular transcription of DNA into RNA, hence the names reverse transcriptase and retrovirus.
  • Reverse transcriptase is central to the infectious nature of retroviruses, several of which cause disease in humans, including human immunodeficiency virus (HIV), which causes acquired immunodeficiency syndrome (AIDS), and human T-cell lymphotropic virus I (HTLV-I), which causes leukemia.
• Bacteria:
  • Bacteria, singular bacterium, any of a group of microscopic single-celled organisms that live in enormous numbers in almost every environment on Earth, from deep-sea vents to deep below Earth’s surface to the digestive tracts of humans.
  • Bacteria lack a membrane-bound nucleus and other internal structures and are therefore ranked among the unicellular life-forms called prokaryotes.
  • Prokaryotes are the dominant living creatures on Earth, having been present for perhaps three-quarters of Earth history and having adapted to almost all available ecological habitats.
  • As a group, they display exceedingly diverse metabolic capabilities and can use almost any organic compound, and some inorganic compounds, as a food source.

Ser - Ajmer is not correctly matched.

• Ser is located in the Sirohi district of Rajasthan.

Additional Information

• The Aravali range virtually runs across as a beam across Rajasthan and bisects the state into two major parts: Southeast Rajasthan and Northwest Rajasthan.
• Aravali range is approximately 692 Kms long, running across Gujarat, Rajasthan, Haryana, and Delhi.
• As a result, Rajasthan has multiple peaks.
• Top Peaks of Rajasthan

The correct answer is chemical energy.

Key Points

• The dry cell is a type of electric battery which is used for portable electrical devices.
• Electricity is produced through the dry cells from electrochemical energy. Hence, Option 1 is correct.
• A common dry cell is a zinc-carbon cell.
• The electrolyte is immobilized as a paste by a dry cell, with just enough humidity in it to allow current to flow.
• Like a wet cell, a dry cell can work without spilling in any direction, because there is no free liquid in it.
• The versatility makes it ideal for mobile devices.
• The first wet-cell batteries, in comparison, were usually fragile glass containers featuring lead rods sticking from an open-top.
• Hence, they required careful handling to prevent spillage.
• The dry-cell battery development made a significant advance in battery safety and portability.
• Batteries render electricity from chemical energy.
• Batteries consist of one or more different parts, or cells, which contain an electrolyte called a chemical.
• Every cell has two electrodes that are electrically conductive immersed in its electrolyte.
• The electrodes consist of different materials; one releases electrons into the electrolyte, and the other absorbs them.
• Once an electrical system is attached to the electrodes, an electrical current passes through it and supports its operation with electric power.
• The energy contained in the dry cell is therefore in the form of chemical energy.

Additional Information

• Thermal energy
  • It is also called heat energy 
  • It is produced when a rise in temperature causes atoms and molecules to move faster and collide with each other.
  • The energy that comes from the temperature of the heated substance is called thermal energy.
  • Thermal energy is energy that comes from a substance whose molecules and atoms are vibrating faster due to a temperature rise.
• In physical sciences, mechanical energy
  • It is the sum of potential energy and kinetic energy.
  • It is the macroscopic energy associated with a system.
  • The principle of conservation of mechanical energy states that if an isolated system is subject only to conservative forces, then the mechanical energy is constant.
• Nuclear power
  • It is the use of nuclear reactions to produce electricity.
  • Nuclear power can be obtained from nuclear fission, nuclear decay, and nuclear fusion reactions.
  • Presently, the vast majority of electricity from nuclear power is produced by nuclear fission of uranium and plutonium in nuclear power plants.

The correct answer is Interconnection and networks.

Key Points

• Internet:
  • The term Internet is derived from the words interconnection and networks. Hence, Option 4 is correct.
  • The Internet (or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices.
  • It is a network of networks that consists of private, public, academic, business, and government networks of local to global scope, linked by a broad array of electronic, wireless, and optical networking technologies.
  • The Internet carries a vast range of information resources and services, such as the inter-linked hypertext documents and applications of the World Wide Web (WWW), electronic mail, telephony, and file sharing. 
  • The first web page address was http://info.cern.ch/hypertext/WWW/TheProject.html.
  • ARPANET adopted TCP/IP on January 1, 1983.
  • NCSA Mosaic ran on Windows computers was the first browser to surf the internet. 

Additional Information

• A computer network is mainly of four types:
  • LAN(Local Area Network)
  • PAN(Personal Area Network)
  • MAN(Metropolitan Area Network)
  • WAN(Wide Area Network)