Quiz Electronics Engineering 25 April 2020

Quiz Electronics Engineering

Exam: NIC

Topic: Miscellaneous

Date:  25/04/2020

 

Each Question carries 1 Mark

Negative Marking:  1/4

Time: 10 Minutes

 

Q1. A network 128.75.0.24 is a

(a) Class A network

(b) Class B network

(c) Class C network

(d) Class D network

 

 

Q2. Repeated execution of simple computation may cause compounding of

(a) round-off errors

(b) syntax errors

(c) run-time errors

(d) logic errors

 

 

Q3. A problem in NP is NP-complete if

(a) Some problem in NP can be reduced to it in polynomial time.

(b) It can be reduced to the 3-SAT problem in polynomial time.

(c) The 3-SAT problem can be reduced to it in polynomial time.

(d) It can be reduced to any other problem in NP in polynomial time.

 

 

Q4. Which of the following desired features are beyond the capability of relational algebra?

(a) Aggregate computation

(b) Finding transitive closure

(c) Multiplication

(d) All of the above

 

 

Q5. Functional testing is related to:

(a) structural testing

(b) behavior testing

(c) regression testing

(d) none of the above

 

 

Q6. In analyzing the compilation of PL/I program the description “creation of more optimal matrix” is associated with

(a) assembly and output

(b) machine independent optimization

(c) code generation

(d) syntax analysis

 

 

Q7. The term ‘aging’ refers to

(a) booting up the priority of the process in multi-level of queue without feedback.

(b) gradually increasing the priority of jobs that wait in the system for a long time to remedy infinite blocking

(c) keeping track of the following a page has been in memory for the purpose of LRU replacement

(d) letting job reside in memory for a certain amount of time so that the number of pages required can be estimated accurately.

 

 

Q8. By using an 7- bit optical encoder the degree of resolution that can be obtained is (approximately)

(a) 1.8o

(b) 3.4o

(c) 1.4o

(d) 2.8o

 

 

Q9. In FM, if the modulation index increases, the number of significant sidebands

(a) increases

(b) decreases

(c) remains same

(d) none of these.

 

 

Q10. Which one of these is a state in thyristor?

(a) Reverse blocking mode

(b) Forward blocking mode

(c) Forward conducting mode

(d) All of these

 

 

 

SOLUTIONS

 

 

S1. Ans.(b)

Sol.

Class A——-1.0.0.1 to 126.255.255.255—————–  for all purpose

Class B——-128.0.0.0 to 191.255.255.255————–  for all purpose

Class C——-192.0.0.0 to 223.255.255.255————— for all purpose

Class D——-224.0.0.0 to 239.255.255.255————– for multicast groups.

Class E——-240.0.0.0 to 254.255.255.255————— for R&D purposes.

 

 

S2. Ans.(a)

Sol.

  • In round-off error, we get the difference of the approximated value and the exact value. When repeated execution of simple computation takes place in this then it causes compounding of round-off errors.
  • A syntax error is an error in the syntax of a sequence of characters or tokens that is intended to be written in compile-time.
  • A runtime error is a program error that occurs while the program is running.
  • A logic error is a bug in a program that causes it to operate incorrectly. It gives wrong output.

 

 

S3. Ans.(b)

Sol. NP is Non-deterministic Polynomial time.  “YES/NO” instances of these problems can be solved in polynomial time by a non-deterministic Turing machine and these problems can be verified(either it is correct or wrong) in polynomial time by a deterministic Turing machine. When all NP problems is reduced to NP complete in polynomial time then a problem in NP becomes NP complete. 3-SAT being an NPC problem, reducing it to a NP problem would mean that NP problem is NPC.

 

 

S4. Ans.(d)

Sol. Relational algebra is a procedural query language which provides theoretical foundation for relational databases and SQL. It accepts instances of relations as input and produces instances of relations as output. The output of these operations is a new relation, which might be formed from one or more input relations. It uses operators to perform queries. An operator can be either unary or binary.

 

 

S5. Ans.(c)

Sol:

Regression Testing is used to select test cases partially or fully to ensure existing functionalities works fine.

Functional Testing is a  software testing in which the system is tested against the functional specifications, by providing appropriate input, verifying the output against the functional specifications. It is a type of black-box testing. The testing can be done either manually or using automation.

Examples of Functional testing are

  • Unit Testing
  • Integration Testing
  • White box testing
  • Black Box testing
  • User Acceptance testing
  • Regression Testing

 

 

S6. Ans.(b)

Sol. Machine independent optimization attempts to improve the intermediate code to get a better target code. Intermediate code transformed does not involve any absolute memory location or any CPU registers.

 

 

S7. Ans.(b)

Sol. In the Priority scheduling algorithm, the low priority processes does not get opportunity to use CPU because of high priority process. Aging is used for solving this problem. Ageing is a scheduling technique used to avoid starvation by increasing the priority of the jobs that wait in the system for a long time or may be for infinite time, by preventing it from blocked for infinite time.

 

 

S8. Ans.(d)

Sol. We know that,

Degree of resolution for n-bit optical encoder =

For 7-bit optical encoder,

Resolution =   =     = 2.80(approx.)

 

 

S9. Ans.(a)

Sol. In FM, if the modulation index increases, the number of significant sidebands increases.

We know that, BW of FM = 2(β+1)

As β increase, so BW increases and due to this the number of significant sidebands also increases.

 

 

S10. Ans.(d)

Sol. There are three states in a thyristor

  • Reverse blocking mode– diode blocks the applied voltage.
  • Forward blocking mode– the voltage applied in a direction makes a diode to conduct. But due to Thyristor had not triggered, no conduction takes place.
  • Forward conducting mode– The thyristor has triggered and current will flow through the device until the forward current reaches below the threshold value, known as “Holding current”.

 

 

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