Question Discussion & Solution

Saw is used for cutting wood.

Similarly, Scythe is used for cutting Grass.

 CONCEPT:

• Electromagnetic waves or EM waves (Lightwave): The waves that are formed as a result of vibrations between an electric field and a magnetic field and they are perpendicular to each other and to the direction of the wave is called an electromagnetic wave.
• The accelerating charged particle produces an electromagnetic (EM) wave.
• A charged particle oscillating about an equilibrium position is an accelerating charged particle.
• Electromagnetic waves do not require any matter to propagate from one place to another as it consists of photons.
• Hence they can move in a vacuum 

Properties of Lightwaves:

• Not have any charge or we can say that they are neutral.
• Propagate as a transverse wave with both wave and particle nature.
• They move with the velocity the same as that of light i.e 3 × 108 m/s.
• It contains energy and they also contain momentum.
• They can travel in a vacuum also and always travel in a straight line.

EXPLANATION:

• All of the above-given statements are true.
• Light travels in a straight line until its path is obstructed.
• Light has dual nature, that is, it shows both waves as well as particle nature.
• Light is a transverse wave as the particles of lightwave vibrate in a direction perpendicular to the direction of propagation.

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 correct answer is Rani Kanakwati.

• Jagat Shiromani Temple:
  • It was constructed by Rani Kanakwati.
  • It is dedicated to Lord Vishnu and Meera bai.
  • It is also known as Meera bai temple as Meera bai was a devotee of Lord Krishna and considered him as her husband.
  • It is situated near the Amer palace.
  • It was built in the memory of queen Kanakwati's son, Jagat Singh.

Additional Information

• Man Singh I:
  • He was the Kachwaha Rajput Raja of Amer.
  • He was the trusted general of the Mughal empire and also one among the Navratanas of Akbar's court.
  • Queen Kanakwati was the wife of Man Singh I.
• Jagat Singh:
  • He was the son of Man Singh I and queen Kanakwati.
  • Jagat Shiromani Temple was built in his memory.
• Jai Singh I:
  • He was the ruler of the kingdom of Amer from 1611 to 1667.
  • He was also the senior general of the Mughal empire. 

Concept:

ArithmeticException is an unchecked exception in Java. Usually, one would come across java. lang. ArithmeticException: Divide ( / ) by zero which occurs when an attempt is made to divide two numbers and the number in the denominator is zero

Code snippet:

int a = 0;

int b = 10/a      // divide by zero exception.

Additional Information 

• A null pointer exception is thrown when an application attempts to use null in a case where an object is required. These include: Calling the instance method of a null object. Accessing or modifying the field of a null object.
• Signals that a method has been invoked at an illegal or inappropriate time. In other words, the Java environment or Java application is not in an appropriate state for the requested operation
• The array index out of bounds error is a special case of the buffer overflow error. It occurs when the index used to address array items exceeds the allowed value. It's the area outside the array bounds which is being addressed, that's why this situation is considered a case of undefined behavior..