Question Discussion & Solution

The correct answer is ​Wide Area Network (WAN).

Key Points

• A global system of interconnected computers, using a standardized Internet Protocol suite for communication and sharing information is called the Internet.
• World Wide Web or ‘www’ is a collection of web pages that can easily be published on the Internet and read by millions of its users. 
• The first development was the introduction of host-to-host network interactions.
• This was first observed in ARPANET in 1969.
• It was developed by the Advanced Research Projects Agency (APRA) of the Department of Defence, U.S. It was one of the first general usages of computer networks.

Important Points

• A personal area network, or PAN, is a computer network organized around an individual person within a single building. This could be inside a small office or residence.
• A typical PAN would include one or more computers, telephones, peripheral devices, video game consoles, and other personal entertainment devices.
• A local area network, or LAN, consists of a computer network at a single site, typically an individual office building. A LAN is very useful for sharing resources, such as data storage and printers.
• LANs can be built with relatively inexpensive hardware, such as hubs, network adapters, and Ethernet cables.
• A metropolitan area network, or MAN, consists of a computer network across an entire city, college campus, or small region. A MAN is larger than a LAN, which is typically limited to a single building or site.
• Depending on the configuration, this type of network can cover an area from several miles to tens of miles. A MAN is often used to connect several LANs together to form a bigger network.
• When this type of network is specifically designed for a college campus, it is sometimes referred to as a campus area network, or CAN.
• A wide area network, or WAN, occupies a very large area, such as an entire country or the entire world. A WAN can contain multiple smaller networks, such as LANs or MANs. The Internet is the best-known example of a public WAN. 

After reading statement and conclusion we say that -

i) All people who are good at dance are pianists. → False (We cannot say that all good dancer are pianists)

ii) Some people who are good at dance are pianists. → True ( As all pianists are good dancer means some of the good dancers are pianists) 

Hence, "Only conclusion ii) follows" is the correct answer.

The correct answer is option 2 i.e 19.

• Potassium is a member of the alkali group of the periodic table.
  • Symbol: K.
  • Atomic number: 19.
  • Belongs to group 1 in the periodic table.
  • First isolated in 1807 by Humphry Davy.
  • Sodium and Potassium are the elements known as soft metals(can cut with a knife with little force).
  • Potassium metal is kept in kerosene due to its high reactivity with water.
  • Potassium bicarbonate is the chemical used in fire extinguishers.
  • Potassium is the most common radioisotope in the human body.
  • Potassium is the second least dense metal after lithium.
• Atomic Number 17: Chlorine.
• Atomic Number 18: Argon.
• Atomic Number 20: Calcium.

The correct answer is Mirage.

• To a distant observer, the light appears to be coming from somewhere below the ground.
• The observer naturally assumes that light is being reflected from the ground, say, by a pool of water near the tall object.
• Such inverted images of distant tall objects cause an optical illusion to the observer.
• This phenomenon is called a mirage.
•  The optical illusion which occurs mainly in the desert during hot summer is based on the principle of TIR i.e total internal reflection.
• This type of mirage is especially common in hot deserts.

Additional Information

• Total Internal Reflection (TIR): When a ray of light goes from denser to the rarer medium it bends away from the normal and as the angle of incidence in denser medium increases, the angle of refraction in the rarer medium also increases and at a certain angle, angle of refraction becomes 90°, this angle of incidence is called critical angle (C).
• When the Angle of incidence exceeds the critical angle then the light ray comes back into the same medium after reflection from the interface. This phenomenon is called Total internal reflection (TIR).
• Conditions for TIR: 
  1. The ray must travel from denser medium to rarer medium.
  2. The angle of incidence 'i' must be greater than the critical angle C.

The correct answer is In 1959.

• In 1959 the Rajasthan Zamindari and Biswedari Abolition Act passed.

Key Points

• Rajasthan Zamindari and Biswedari Abolition Act
  • This Act may be called the Rajasthan Zamindari and Biswedari Abolition Act, 1959.
  • It extends to the whole of the State of Rajasthan.
  • In this Act, unless the subject or context otherwise requires,-
    • "Biswedar" has the meaning assigned to it by clause (5) of Section 5 of the Rajasthan Tenancy Act, 1955 (Rajasthan Act 3 of 1955).
  • "estate" means land, or right, title or interest in land, held by a Biswedar or a Zamindar;
  • "settled" has the meaning assigned to it by clause (n) of Section 2 of the Rajasthan Land Reforms and Resumption of Jagirs Act, 1952 (Rajasthan Act 6 of 1952);
  • "Zamindar" has the meaning assigned to it by clause (46) of Section 5 of the Rajasthan Tenancy Act, 1955 (Rajasthan Act 3 of 1955) and includes a malik (landowner) in the Gang Canal area.

Additional Information

• Significance of the Rajasthan Zamindari and Biswedari Abolition Act
  • ​As soon as after the commencement of this Act, the State Government by notification in the Official Gazette ordered for the abolition and acquisition of Zamindari and Biswedari estates, or any class of such estates, in the State, or in any area thereof specified in the notification, and for their vesting in the State Government.