Question Discussion & Solution

The correct answer is Curvature of the lens.

Important Points

• Focal length of a lens depends on its curvature and the medium outside the lens.

Additional Information

• The ability of a lens to converge or diverge light rays depends on its focal length.
  • For example, a convex lens of short focal length bends the light rays through large angles, by focussing them closer to the optical centre.
  • Similarly, the concave lens of a very short focal length causes a higher divergence than the one with a longer focal length.
• The degree of convergence or divergence of light rays achieved by a lens is expressed in terms of its power.
  • The power of a lens is defined as the reciprocal of its focal length.

Explanation:

• Evolutionary biology: It is a field of science that deals with the study of evolutionary processes like natural selection, speciation & common descent that has led to the diversification of life on earth.
• Charles Darwin is known as the father of ''Evolutionary Biology''.
• Darwin proposed a theory of evolution called natural selection in the year 1859. According to it those populations which are a better fit (reproductively fit) in an environment will be selected by nature and will survive more.
• Charles Darwin wrote a book named ''The origin of species'' which is considered to be the foundation of evolutionary biology.

Additional Information 

• Herbert Spencer- He Was best known for the introduction and application of evolutionary theory to philosophy, psychology, and social sciences
• The famous phrase 'Survival of the fittest' to mean Natural Selection was coined by Herbert Spencer. He originated this phrase after the publication of famous biologist Charles Darwin’s book ‘Origin of Species’ which talked about ‘Natural Selection’.
• Julian Huxley was an English biologist, philosopher, educator, and author who greatly influenced the modern development of embryology, systematics, and studies of behaviour and evolution.
• Stanley Miller along with H.C. Urey provided experimental evidence of ''chemical evolution''

The logic followed is:

L, M, X, Y and Z each having a different salary.

i) X is getting more salary than only M.

X > M

Important Points

As the word only is used this means X's salary is only greater than M.

ii) L is getting less salary than Y, who is not getting the highest salary.

Y > L but Y is not getting the highest. Y's salary is greater than L.

Mistake Points

Who is used for the second person in a connecting statement.

For example, in the above question : 

L is getting less salary than Y, who is not getting the highest salary.

Here, who is used for Y and not for L.

Thus combining the both we get:

Z > Y > L > X > M.

Thus Z is getting the highest salary.

Hence, the correct answer is "Z".

The correct answer is Single-User Operating System.

Important Points

• Single-User Operating System
  • Performs a single task for Single-user.
  • This operating system is designed to manage the computer so that one user can effectively do one thing at a time.
  • Examples include Microsoft Windows.

Additional Information

• The different types of Operating System:
• Batch Operating System
  • There is no direct communication between the computer and the OS.
  • There is an intermediate, the Operator.
  • The operator distributes the work into batches.
• Real-Time Operating System
  • The processing time is very small between the user’s command and the output such that there is no operator.
• Time-Sharing Operating System
  • Multiple people at various computers can use a program at the same time.
• Distributed Operating System
  • When two or more systems are connected to each other and one can open each other's files.
• Embedded Operating System
  • These special Operating systems are built into larger systems.
  • They are limited to single specific functions like an ATM.
• Network Operating System
  • They have one main server which is connected to other client servers.
  • It provides a secure operating system for working with multiple users.

The first two statements give information about payal, monika and Sonam. Information about kunal and monika cannot be determined.