Question Discussion & Solution

Length is measured in Meter.

Similarly,

Power is measured in Watt.

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

The correct answer is Vivek Ram Chaudhari.

Key Points

• Air Marshal Vivek Ram Chaudhari has been named as the next Chief of Air Staff.
  • He succeeds Air Chief Marshal RKS Bhadauria who will retire from service in the end of September 2021.
  • Currently posted as the Vice Chief of Air Staff, the officer was commissioned into the fighter stream and has commanded a MiG 29 squadron and has experience of various types of aircraft including the SU 30MKI.

Concept:

• Atoms are made up of subatomic particles - electrons protons and neutrons.
• In the center of an atom, a nucleus is present which contains protons and neutrons together known as nucleons.
• The mass of an atom is most concentrated at the center of the atom, i.e. the nucleus.

​Electrons:

• Discovered by Sir J.J Thomson in the year 1897.
• Previously named as cathode rays as they were supposed to be emitted from the cathode.
• They are deflected towards the positive side.
• They have high kinetic energy.
• They are deflected by an electric and magnetic field.
• It has a negative charge of

  \(charge=1.602\times10^{-19} coulombs \)
\(mass={1\over 1837}\times 9.107\times 10^{-28}g\)

Protons:

• Discovered by Goldstein.
• Depicted first as positive rays because it seemed to emerge from the anode.
• Mass of a proton is

 \(1.670 \times 10^{- 24}g\)

\(Charge=1.602\times 10^{-19} coulombs\)​

Explanation:

• Rutherford's discovery led to the discovery of nucleus.
• He found out that most of the mass of the nucleus is situated in its centre and contains the positively charged particles protons.
• The atom is otherwise empty and as electrons have negligible mass, the mass of an atom should be equal to the sum of mass of protons present in it.
• However, it was seen that in Helium, there are only two protons, so its mass should be twice the mass of each proton = \(2\times 1.008 a.m.u\).
• Experimental results revealed that it has a mass of 4.003a.m.u.
• Hence, it was concluded that the nucleus has particles containing no charge but mass almost equal to that of a proton.
• This was established by scientist James chadwick in 1932.

Additional Information

Rutherford's gold foil experiment: 

• He discovered the atomic nucleus and gave us an atomic model.
• He directed alpha particles towards a metal sheet.
• He saw that most of the alpha particles, which are positively charged particles, are not getting deflected.
• Most of the alpha particles emerged undeflected.

• Therefore, he concluded that most of the mass of the nucleus is situated in its centre and contains the positively charged particles protons.
• Electrons revolve around the nucleus in certain orbits.

The correct answer is All of the Above.

 Key Points

• Decision making structures require that the programmer specifies one or more conditions to be evaluated or tested by the program.
• It also involves a statement or statements to be executed if the condition is determined to be true, and optionally, other statements to be executed if the condition is determined to be false.
• C programming language provides the following types of decision-making statements.
• if...else statement
  • An if statement can be followed by an optional else statement, which executes when the Boolean expression is false.
• switch statement
  • A switch statement allows a variable to be tested for equality against a list of values.
• C goto
  • The goto statement in C/C++ also referred to as the unconditional jump statement can be used to jump from one point to another within a function.

 Additional Information

• C break:
  • This loop control statement is used to terminate the loop.
  • As soon as the break statement is encountered from within a loop, the loop iterations stop there, and control returns from the loop immediately to the first statement after the loop.