Quiz Electronics Engineering 3 Sep 2020

Quiz Electronics Engineering
Exam: NIC
Topic: Miscellaneous
Date: 03/09/2020

Each Question carries 1 Mark
Negative Marking: 1/4
Time: 10 Minutes

Q1. When transistors are used in digital circuits they usually operate in the
(a) active region
(b) break down region
(c) saturated region
(d) saturation and cut off region

Q2. A fetch cycle is the:
(a) First part of the instruction cycle
(b) Last part of the instruction cycle
(c) Intermediate part of the instruction
(d) Auxiliary part of the instruction cycle

Q3. The term “White Noise” refers to the following:
(a) A random signal generated by beat signal
(b) A random signal with flat Power Spectral Density
(c) A random signal with long range correlation
(d) All of the above are true

Q4. The units of the spectrum obtained by Fourier transforming the covariance function of a stationary stochastic process is
(a) power per second
(b) energy per Hertz
(c) power per Hertz
(d) energy per second

Q5. The efficiency of Zener Diode for heavy load current is
(a) Low
(b) zero
(c) very low
(d) Infinity

Q6. Consider the following statements regarding smith charts:
(1) A normalized smith chart applies to a line of any characteristic resistance and serves as well for normalized admittance
(2) A polar co-ordinate smith chart contains circles of constant |Z| and circles of constant ∠Z.
(3) in Smith chart, the distance towards the load is always measured in clockwise direction.
Which of the statements given above are correct?
(a) 1, 2 and 3
(b) 2 and 3
(c) 1 and 3
(d) 1 and 2

Q7. Advanced Encryption Standard (AES) is based on
(a) Asymmetric key algorithm
(b) Symmetric key algorithm
(c) Public key algorithm
(d) Key exchange

Q8. What is the Laplace Transform of cosωt?
(a) ω/〖(s+ω)〗^2
(b) ω/(s^2+ω^2 )
(c) s/(s^2+ω^2 )
(d) s/〖(s+ω)〗^2

Q9. Instruction LHLD 2000H is an example of:
(a) Implied addressing
(b) Direct addressing
(c) Indirect addressing
(d) Register addressing

Q10. Power factor can be improved by
(a) by using transition
(b) by using R-L circuit
(c) by using synchronous motor
(d) None of these

SOLUTIONS

S1. Ans. (d)
Sol. When transistors are used in digital circuits they usually operate in the saturation and cut off region. In Saturation region they act as a Short Circuit i.e., ON(‘1’) and in Cut-off region they act as Open Circuit i.e., OFF(‘0’).

S2. Ans.(a)
Sol. Instruction Cycle consists of fetch cycle and execute cycle. So, A fetch cycle is the first part of the instruction cycle.

S3. Ans.(b)
Sol.

S4. Ans.(c)

S5. Ans.(a)
Sol. In Zener diode, current is limited only by the external resistance and the power dissipation of Zener diode so for heavy load current power dissipation goes high hence it will result low efficiency of the Zener diode.

S6. Ans.(d)
Sol. In Smith Chart, the distance towards the load is always measured in anti-clockwise direction.

S7. Ans.(b)
Sol: Advanced encryption standard (AES) is used in symmetric key algorithm for the encryption of electronic data. It is an iterative rather than Feistel cipher. It is based on ‘substitution–permutation network’ and comprises of a series of linked operations.

S8. Ans.(c)

S9. Ans.(b)
Sol. ‘LHLD 2000H’ is in Direct Addressing Mode. It means data stored in the location 2000 H is loaded in ‘HL register pair’. It is a 16-bit address with 3 byte instructions.

S10. Ans.(c)
Sol. A synchronous motor under over-excited condition operates at a leading power factor. Synchronous motors are therefore employed in large power installations for improving the overall power factor of the installation.

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