Question Discussion & Solution

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.

Concept:

A functional dependency is a constraint between two sets of attributes from the database.

Explanation:

In general form, a functional dependency denoted by X -> Y between two sets of attributes X and Y that are subsets of R specifies a constraint on the possible tuples that can form a relation state r of R.

The constraint is that for any two tuples T₁ and T₂ in r that have T₁[X] = T₂[Y], they must also have T₁[Y]

= T₂[Y]. It means that values of Y component of a tuple in r depend on or are determined by the value of X component.

If a relation R contains attributes (X and Y). Then X -> Y is a functional dependency. It means X functionally determines Y in R if and only if two tuples agree on their X value, they must necessarily agree on their Y value.

The correct answer is Natural Gas.

Key Points

•  Fossil Fuel: Fossil Fuels are the fuels generated from the residues of living organisms (which remained buried under the earth for millions of years).
  • Examples: Coal, Petroleum, and Natural gas.
  • They are also known as Non-Renewable Natural Resources.​

 Additional Information

• Natural Gas: It is considered the best fuel because of the inflammable nature of its constituents(83% methane and 16%ethane).
  • It is used in the production of artificial chemical fertilizers. 
• Coke: It is obtained by the strong heating of coal in the absence of air as a residual substance. 
  • It contains 80-85% carbon.
  • Coke is used in the extension of metals as a reducing agent.
• Producer Gas: It is a mixture of nitrogen and carbon monoxide(in 2:1 ratio).
  • It is used in the manufacture of glass and for metallurgy. 

The correct answer is Operating system.

Key Points

• UBUNTU is an example of an operating system.
• The operating system is a collection of programs that controls the overall operations of the computer.
• Operating systems are of two types namely, Open-source operating systems and Closed source operating systems.
• UBUNTU is free and open-source software.
• Operating systems works as an interface between a user and computer hardware components.
• Examples of operating systems are:
  • Linux
  • Unix
  • DOS
  • Windows
  • Ubuntu
  • Embedded operating system
  • OpenBSD
  • Mac OS

Additional Information

• Malware is a file or code that is designed to damage and destroy computers and computer systems.
  • Viruses, worms, Trojan viruses, spyware are the common examples of malware.
• A web browser is an application used to access and view websites.
  • Google Chrome, Mozilla Firefox, Apple Safari are the common examples of web browsers.

The logic is,

In the first image, there are six lines in the first column and there is a four-sided figure in the second column.

In the second image, there are eight lines in the first column and there is a six-sided figure in the second column.

So, it means that the number of sides of a figure in the second column is decreasing by two from the number of lines in the first column.

Since, in third image there are five lines so the answer figure must be a three-sided figure.

Thus, the correct figure is as follows: