Question Discussion & Solution

Important Points

Email bomb

It is an attack on your inbox that involves sending massive amounts of emails to your address. Sometimes these messages are complete gibberish, but more often they’ll be confirmation emails for newsletters and subscriptions.

Additional Information

Spoofing 

It is the act of disguising a communication from an unknown source as being from a known, trusted source. Spoofing can apply to emails, phone calls, and websites, or can be more technical, such as a computer spoofing an IP address, Address Resolution Protocol (ARP), or Domain Name System (DNS) server.

Smurf Attack

It is a form of a DDoS attack that causes packet flood on the victim by exploiting/abusing ICMP protocol. When deployed, large packets are created using a technique called “spoofing”. The phony source address that is now attached to these packets becomes the victim, as their IP is flooded with traffic. The small ICMP packet generated by the tool causes big trouble for a victim, hence the name Smurf.

Ping storm

It is a condition in which the Internet ping program is used to send a flood of packets to a server to  test its ability to handle a high amount of traffic or, maliciously, to make the server inoperable

Hence Option 1 is correct

 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.

A scalar is a quantity which has only a magnitude but not a direction whereas vector is a quantity which has both a magnitude and a direction.

Volume is a scalar quantity similarly, momentum is a vector quantity while time, speed and energy are the scalar quantities.

Pattern followed is,

D + 6 = J

J + 5 = O

O + 4 = S

S + 3 = V

V + 2 = X

Hence, “O” is the correct answer.

The correct answer is ​CTRL + Z.

• CTRL + Z is used to undo changes (UNDO) in Ms-Word.

​Key Points

• CTRL + Z
  • To reverse the last action done by can be regained using CTRL+Z shortcut.
  • We can reverse more than one action using this shortcut tool.

Additional Information

• CTRL + Y
  • The keyboard shortcut for Redo is CTRL-Y.
• ​​Ctrl+N
  • ​​Ctrl+N is a keyboard shortcut most often used to create a new document, window, workbook, or other types of file.
• CTRL + H
  • Ctrl+H is a keyboard shortcut whose function varies depending on the program.
  • For example, with text editors, Ctrl+H is used to find and replace a character, word, or phrase.
  • In an Internet browser, Ctrl+H opens the history tool.