Question Discussion & Solution

The correct answer is Constellation.

• Ursa Major constellation lies in the northern sky. Its name means “the great bear,” or “the larger bear” in Latin.
• Ursa Major is the largest northern constellation and third largest constellation in the sky.
  • Its brightest stars form the Big Dipper asterism, one of the most recognizable shapes in the sky, also known as the Plough.
• Ursa Major contains seven Messier objects. It also contains 13 stars with confirmed planets.

Important Points

• The biggest known galaxy is IC 1101, which is 50 times the Milky Way's size and about 2,000 times more massive.
  • It is about 5.5 million light-years across.
• Our Sun (a star) and all the planets around it are part of a galaxy known as the Milky Way Galaxy.
  • A galaxy is a large group of stars, gas, and dust bound together by gravity. The Milky Way is made up of about 90% dark matter, the matter which cannot be seen, and about 10% “luminous matter”, or matter that we can see with our eyes.
  • The solar system lies about 30,000 light-years from the galactic centre.

Additional Information

• Sirius, also known as the Dog Star or Sirius A, is the brightest star in Earth's night sky.
• The name means "glowing" in Greek.

The correct answer is the Helium nucleus.

• Helium nucleus was the source of alpha particles in the Rutherford scattering experiment.
• Ernest Rutherford, a British scientist conducted an experiment and proposed the atomic structure of elements.

Key Points

• Rutherford conducted an experiment by bombarding a thin sheet of gold with α-particles.
• He then analysed the trajectory of these particles after their interaction with the gold foil.
• Since very few α-particles were deflected back, and only a few α-particles had nearly 180^o angle of deflection.
• Hence he concluded that the volume occupied by the positively charged particles in an atom is very small as compared to the total volume of an atom.

The correct answer is Western disturbances.

Key Points

• Western Disturbances are responsible for the rainfall during winter over the northwestern part of India.
• The Western Disturbance originates in the mid-latitude region near Europe and the Atlantic Ocean.
  • The low pressure builds up over the Mediterranean Sea and moves over Iraq, Afghanistan, and Pakistan before entering India, and contains substantial amounts of moisture.
  • When these low-pressure systems reach the Indian subcontinent, they are blocked by the Himalayas and rain as snow over the northwestern plains and the higher reaches of the western Himalayas.
  • After precipitation over northwest India, they weaken and are devoid of moisture, they blow as dry winds that form dense fog over the northern plains of India.

Additional Information

• The period June to September is referred to as the Southwest Monsoon period.
  • Southwest Monsoon period is the principal rainy season for the Indian subcontinent.
  • This is the summer monsoon period where the southwest monsoon holds away over the country.
  • The whole country receives nearly 75% of its rainfall during this period.

Malware Protection is not the main function of the operating system.

Important Points

• Malware Protection
  • Malware is any software intentionally designed to cause damage to a computer, server, client, or computer network.
  • A range of antivirus software, firewalls and other strategies are used to protect against the introduction of malware.

Key Points

• Operating system
  • An operating system is a large and complex system.
  • OS system components include:
    • File,
    • Process,
    • Memory,
    • I/O device management.

 Additional Information

• The process management component
  • The process management component is a procedure for managing the many processes that are running simultaneously on the operating system.
  • Every software application program has one or more processes when they are running.
  • For example, when we use a browser like Google Chrome, there is a process running for that browser program.
  • All these processes managed by process management. 
  • The process management uses memory allocated to them and shutting them down when needed.
• File management
  • File management in an operating system includes file creation and deletion.
  • Manipulating files and directories.
• Memory management
  • ​An Operating System performs the functions for Memory Management such as:
    • It helps to keep track of primary memory.
    • Determine what parts of it are in use by whom, what part is not in use.
• I/O device management
  • ​An Operating System performs the functions for I/O device management such as:
    • It offers buffer caching system
    • It provides general device driver code
    • It provides drivers for particular hardware devices.

The correct answer is 1 i.e. propanal.

Concept:

IUPAC nomenclature:

• A systematic method of naming organic compounds.
• Naming is based on their structures.
• It is devised by the International Union of Pure and Applied chemistry.
• Many rules are followed while naming the compounds and it is different for different functional groups.
• The rules are known as IUPAC rules.

Explanation:

• This compound contains 3 carbon atoms, so its parent alkane is propane.
• It also contains an aldehyde group (-CHO-) group which is indicated by using 'al' as suffix or ending.
• So by replacing the last 'e' of butane with 'al', the name becomes propanal.
• Thus, the IUPAC name of the compound CH3CH2CHO is propanal.
• The common name of propanal is Propionaldehyde.

​Additional Information

• The chart for priority order and suffix name is given below: