Quiz Electronics Engineering 27 March 2020

Quiz Electronics Engineering

Exam: NIC

Topic: Miscellaneous

Date:  26/03/2020

 

Each Question carries 1 Mark

Negative Marking:  1/4

Time: 10 Minutes

 

Q1. Which of the following is a trap set to detect, deflect or in some manner counteract attempts at unauthorized use of information systems?

(a) Honey pot

(b) Firewall

(c) Cryptography

(d) Botnet

L1 Difficulty 3

QTags Networking

QCreator Vikram Kumar

 

Q2. Which of the following is not usually part of the responsibilities of a database administrator?

(a) Approving structural changes to the database

(b) Ensuring that an adequate back-up regime is in place

(c) writing stored procedures and triggers.

(d) Issuing accounts to users and monitoring the performance of the system.

L1 Difficulty 4

QTags DBMS

QCreator Vikram Kumar

 

Q3. In which type of cryptography same key is used as encryption and decryption?

(a) Symmetric cryptography

(b) Asymmetric cryptography

(c) Key cryptography

(d) Encryption cryptography

L1 Difficulty 3

QTags DBMS

QCreator Vikram Kumar

 

Q4. The wavelength of a wave with propagation constant (0.1π + j0.2π ) m-1 is

(a)2/√0.05 m

(b)30 m

(c)20 m

(d)10 m

L1 Difficulty 3

QTags Electromagnetic Theory

QCreator Vikram Kumar

 

Q5. An independent voltage source in series with an impedance ZS = RS + jXS, delivers a maximum average power to a load impedance ZL, when

(a)ZL = RS – jXS

(b)ZL = RS + jXS

(c)ZL = RS

(d)ZL = jXS

L1 Difficulty 2

QTags Network & Circuit Theory

QCreator Vikram Kumar

 

Q6. The signal to quantization noise ratio in an n-bit PCM system

(a)depends upon the sampling frequency employed

(b)is independent of the value of ‘n’.

(c)increases with increasing value of ‘n’.

(d)decreases with the increasing value of ‘n’.

L1 Difficulty 3

QTags Communication Engineering

QCreator Vikram Kumar

 

Q7. The impulse response of an LTI system can be obtained by

(a)differentiating the unit ramp response

(b)differentiating the unit step response

(c)integrating the unit ramp response

(d)integrating the unit step response

L1 Difficulty 2

QTags Signals and systems

QCreator Vikram Kumar

 

Q8. The Boolean function A + BC is a reduced form of

(a)AB+ BC

(b)(A + B) . (A + C)

(c)A`B + AB`C

(d)(A + C).B

L1 Difficulty 3

QTags Digital Electronics

QCreator Vikram Kumar

 

 

Q9. Which is NOT the part of operating procedure manuals?

(a)a User manuals

(b)Operational manuals

(c)Installation manuals

(d)Documentation manuals

L1 Difficulty 3

QTags Software Engineering

QCreator Vikram Kumar

 

Q10. A hardware interrupt is

(a)also called an external interrupt

(b)also called an internal interrupt

(c)an I/0 interrupt

(d)a clock interrupt

L1 Difficulty 3

QTags Computer Organization & Microprocessor

QCreator Vikram Kumar

 

SOLUTIONS

 

S1. Ans.(a)

Sol.

  • A Honeypot is a security system designed to detect and counteract unauthorized access or use of a computer system. The name “HONEYPOT” is used in reference to the way the system traps unauthorized users, such as hackers or spammers so they can be identified and prevented from causing further problems.
  • A Firewall is a network security system. It monitors and controls incoming and outgoing network traffic based on predetermined security rules. We can implement a firewall in either hardware or software form, or a combination of both. It prevents unauthorized internet users from accessing private networks connected to the internet, especially intranets.
  • Cryptography is a method of protecting information with the use of codes so that only those for whom the information is intended can read and process it. It is also for secure communication in the presence of third parties called Adversaries.
  • Botnets are networks of computers infected by malware such as computer viruses, key loggers and controlled remotely by criminals. It performs distributed denial-of-service attack (DDoS attack), steal data, send spam, and allows the attacker to access the device and network.

 

S2. Ans.(c)

Sol.  Database administrators (DBAs) use specialized software to store and organize data. The role may include capacity planning, installation, configuration, database design, migration, performance monitoring, authentication, security, troubleshooting, as well as backup and data recovery.

 

S3. Ans.(a)

Sol.

  • In symmetric key cryptography, same key is shared, i.e. the same key is used in both encryption and decryption.
  • Asymmetric cryptography is also called as Public-key cryptography. It has a secret key which is divided into pairs of keys: public keys which may be disseminated widely, and private keys which is known to the owner only.

 

S4. Ans.(d)

Sol.

We know Propagation constant is

γ = α + jβ  =  0.1π  + j0.2π                  and                    β =

Comparing real and imaginary part, we get

β = 0.2π =

So,                   λ =  = 10m

 

S5. Ans.(a)

Sol.

Zs = RS + jXS

For maximum power transfer,

ZL =

So,                               ZL = RS – jXS

 

S6. Ans.(c)

Sol.

The Signal to Quantization noise ratio of an n-bit PCM system is given by

  • (SQNR)dB = 1.76 + 6n where, n is number of bits
  • SQNR = 22n

From above equation, we can see that SQNR increases with increase in value of ‘n’.

 

S7. Ans.(b)

Sol.

S.No. Original Signal Differentiated Signal Integrating Signal
1. Impulse 1 Step
2. Step Impulse Ramp
3. Ramp Step Parabolic

Impulse response:

IR =

Step response:

y(t) =

Differentiating both side, we get

h(t) =

Similarly others can be calculated.

 

S8. Ans.(b)

Sol. Option (a) and (d) are same but both cannot be solved further. So we can exclude those 2.

Option (b):       (A+B).(A+C)

= A.A+ A.C + A.B + B.C

= A + AC + AB +BC

= A(1+C+B) + BC = A +BC

 

S9. Ans.(d)

 

S10. Ans.(a)

Sol.

  • A hardware Interrupt Request (IRQ) is issued by a hardware device which is external to the processor, to communicate that the device needs attention from the operating system or if no OS then from the program running on the CPU. External devices may be part of the computer or peripherals. It can be either maskable or non-maskable. In it all the devices are connected to the single Interrupt Request Line(IRL).
  • An External Interrupt also called as “Hardware interrupts” happens due to outside interference, from the user, from peripherals, from other hardware devices or through a network.
  • An internal interrupt also known as “Software interrupts” is caused by a machine instruction processed by the computer processor.

 

 

 

Leave a comment

Your email address will not be published. Required fields are marked *