Question Discussion & Solution

The correct answer is Charles Babbage.

• Charles Babbage is considered to be the ‘Father of Modern Digital Computer’.

Key Points

• Digital computer, any of a class of devices capable of solving problems by processing information in discrete form.
  • It operates on data, including magnitudes, letters, and symbols, that are expressed in binary code—i.e., using only the two digits 0 and 1.
  • Examples of digital electronic computers include the IBM PC, the Apple Macintosh as well as modern smartphones.
• Today computers are being used almost everywhere like schools, colleges, hospitals, offices, railway stations, hotels, etc.
• A computer system is multitasking so that you can do two tasks very easily at the same time.

Additional Information

• Storage Capacity of Computer
  • Computer systems have a very large capacity to store any type of data.
  • A computer can store and resell any information due to its storage capacity. 
  • Computers have the ability to store all types of data such as data, pictures, files, programs, games, and sound for many years and later we can get any data in a few seconds at any time for taking that information and for future retrieval.
• Reliability of Computer
  • Reliability is a very big characteristic of computers.
  • Today almost all the big industries or big e-Commerce companies like Amazon and Flipkart, and big search engine companies like - Google and Bing, all these companies are dependent on computers. 
  • Today every major industry and company in the world has full confidence in their computers, and their entire business is running from computers.
• Diligence of Computer
  • A person gets tired of doing some work in a few hours and a computer has the ability to do any work continuously for many hours, days, months. 
  • Even after the computer has worked for such a long time, there is no decrease in its ability to work and its accuracy.
  • The computer does work without any discrimination.
    • A computer is free from monotony and tiredness.
• Accuracy of Computer
  • A computer is very accurate.
    • It does not make any kind of mistake in calculating.
    • Sometimes we get some errors but these are because of the mistake performed by us.
  • The Accuracy of the computer is constantly high and it can perform hundreds of operations with the carry-out calculation and analysis accurately and speedily.

CONCEPT:

• It is the property of liquid by virtue of which the free surface of the liquid at rest acting like a stretched membrane trying to contract to reduce its surface area.
• Surface tension is a force per unit length (or surface energy per unit area) acting in the plane of interface between the liquid and the bounding surface.
• It is the extra energy that the molecules at the interface have as compared to the interior.
• The surface tension is the force acting perpendicular on a unit length of an imaginary line drawn on the surface of the liquid and it can be expressed as

\(\Rightarrow T = \frac{F}{l}\)

• Because of this surface tension, few insects can easily float on liquid surface similarly a needle can be made to float on the surface of liquid using this principle

Here,

T = surface tension,

F = force acting on the surface (Cohesive force)

l = unit length

EXPLANATION:

• As explained above, the surface tension acting on a fluid surface can be expressed as

Surface tension, \(T = \frac{{{\rm{The\;cohesive\;force\;between\;molecule}}}}{{unit\;length}}\) 

• Also, we know that cohesive force or the attractive force between the liquid molecules is inversely proportional to its temperature.
• Since as we increase the temperature of fluid its interatomic distance will keep on increasing hence it will cause a decrease in the surface tension of the fluid.

i.e., \(surface\;tension,\;T \propto \frac{1}{{temperature}}\)

So, only option 3^rd is correct.

The correct answer is a Female egg cell.

The female egg cell is the largest cell in the human body. The nerve cell is the longest cell in the body.

• The egg cell or ovum is the largest cell in the human body.
• It has a diameter of about 0.1 mm.
• A nerve cell is the longest cell in the human body.
• Muscle cells are the primary cells responsible for the movement of the body. There are three types of muscle cells found in our body, namely ;
  • Skeletal muscle or voluntary muscle.
  • Smooth muscle or involuntary muscle.
  • Cardiac muscle.

Mistake Points

• The smallest cell is Mycoplasma (PPLO-Pleuro pneumonia-like organisms).
• It is about 10 micrometres in size.
• The largest cell is an egg cell of ostrich.
• The longest cell is the nerve cell.
• The largest cell in the human body is the female ovum.
• The smallest cell in the human body is the male gametes, that is, sperm.

Here the pattern is,

3 × 1 = 3,

1 + 3 = 4,

3 × 4 = 12,

4 + 12 = 16,

Similarly, we have:

12 × 16 = 192

402° - 302° = 100° in North-East direction