Question Discussion & Solution

final is used to apply restrictions on class, method, and variable. final is a keyword.

finally is used to place important code, it will be executed whether an exception is handled or not.

System is a class. finalize and main are methods.

The correct answer is Archimedes' principle.

Concept:

Archimedes principle:

the principle of Archimedes states “When a body is immersed in a liquid, an upward thrust, equal to the weight of the liquid displaced, acts on it.”

Thus, when a solid is fully immersed in a liquid, it loses weight which is equal to the weight of the liquid it displaces.

i.e., \(Apperent\;weight = actual\;weight - buoyant\;force = mg - \rho gV\)

where m is mass of the object, ρ is the density of the fluid

Hence if there is no gravity, there is no Upward Thrust.

The upward force applied to the object is called the buoyant force.

Here,

ρ = density of liquid

g = acceleration due to gravity

V = volume of liquid displaced by the object

Explanation:

Archimedes’ principle, a physical law of buoyancy states that any body completely or partially submerged in a fluid (gas or liquid) at rest is acted upon by an upward, or buoyant, force the magnitude of which is equal to the weight of the fluid displaced by the body.

Hence floating of the ship is based on Archimedes principle:

An electrician wears rubber gloves to avoid electric shock while repairing an electrical switch.

• As the human body is a good conductor of electricity.
• So it can pass through electricity from itself when it comes in contact with electricity and may get shocked or even fatality.
• As rubber is an insulator i.e. it is a non-conductor of electricity.
• So it protects the body of electricians from direct contact with electricity.

The correct answer is Aravali.

• Aravali range forms the main water area for Rajasthan.

Key Points

• Aravali range​
  • The Aravallis of Northwestern India, one of the oldest fold mountains of the world, now form residual mountains with an elevation of 300m. to 900m.
  • They stretch for a distance of 800 km from Himmatnagar in Gujarat to Delhi, spanning Haryana, Rajasthan, Gujarat, and Delhi, the 692 kilometres (km).
  • The Aravallis act as a barrier between the fertile plains in the east and the sandy desert in the west.
  • Historically, it is said that the Aravalli range checked the spread of the Thar desert towards the Indo-Gangetic plains, serving as a catchment of rivers and plains.
  • Thus Aravali range forms the main water area for Rajasthan.

​Additional Information

•  Aravali range formation
  • ​These are fold mountains of which rocks are formed primarily of the folded crust when two convergent plates move towards each other by the process called orogenic movement.
  • The Aravallis date back to millions of years when a pre-Indian sub-continent collided with the mainland Eurasian Plate.
  • Carbon dating has shown that copper and other metals mined in the ranges date back to at least the 5th century BC.

• For most computer languages, the name of the file that holds the source code to a program is immaterial
• However, in Java the name given to a source file is very important
• The Java compiler requires that a source file uses the .java filename extension
• Only file.java follow the properties in the given options
• In Java, a source file is officially called a compilation unit; It is a text file that contains one or more class definitions