Quiz Electronics Engineering 7 Aug 2020

Quiz Electronics Engineering
Exam: NIC
Topic: Miscellaneous
Date: 07/08/2020

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

Q1. Three capacitors of value 8μF, 16μF and 32μF are connected in series, the total capacitance will be
(a) 32/7μF
(b) 7.32 μF
(c) 56 μF
(d) 32 μF

Q2. Consider the following codes:
1. Hamming code
2. Huffman code
3. Shannon-Fano code
4. Convolutional code
Which of these are source codes?
(a) 1 and 2 only
(b) 2 and 3 only
(c) 3 and 4 only
(d) 1, 2, 3 and 4

Q3. The line of sight communication requires transmitter and receiver antenna to face each other. If the transmitting antenna is vertically polarized, for the best reception the receive antenna should be:
(a) Horizontally polarized
(b) Vertically polarized
(c) At 45° with respect to the horizontal polarization
(d) At 45° with respect to the vertical polarization

Q4. If decimal 10 in binary is 1010, then decimal 100 in binary will be
(a) 1111111
(b) 1110100
(c) 1100100
(d) 1000100

Q5. A continuous-time system is governed by the equation 3y^3(t) + 2y^2(t) + y(t) = x^2(t) + x(t). { y(t) and x(t) respectively are output and input}. The system is
(a) linear and dynamic
(b) linear and non-dynamic
(c) non-linear and dynamic
(d) non-linear and non-dynamic

Q6. The tendency of charge carriers to move from a region of heavily concentrated charges to region of less concentrated charge is known as.
(a) Depletion current
(b) Drain current
(c) Diffusion current
(d) Saturation current

Q7. The Op-Amp circuit shown below represents a

(a) High Pass Filter
(b) Low Pass Filter
(c) Band Pass Filter
(d) Band Reject Filter

Q8. Octal coding involves grouping the bits in
(a) 3’s
(b) 4’s
(c) 5’s
(d) 7’s

Q9. A passive network has
(a) current sources but no voltage sources
(b) voltage sources but no current sources
(c) both current and voltage sources
(d) no voltage or current sources

Q10. The color TV picture signal is a
(a) single-channel, one-dimensional signal
(b) single-channel, three-dimensional signal
(c) three-channel, one-dimensional signal
(d) three-channel, three dimensional signal

SOLUTIONS

S1. Ans.(a)
Sol. For series connected capacitor, total capacitance (CT) is –
⇒ 1/C_T =1/C_1 +1/C_2 +1/C_3
⇒ 1/C_T = 1/8+1/16+1/32
⇒ 1/C_T =(4 + 2 + 1)/32=7/32
So, C_T=32/7 μF

S2. Ans.(b)
Sol. Source Codes are:-
Huffman code
Shannon-Fano code
Error Correcting Codes are:-
Hamming codes
Convolution codes

S3. Ans.(b)
Sol. For best reception in LOS communication both transmitting antenna and receiving antenna should face each other and must be in same polarization. If not in same polarization then fading or losses of signal may takes place. As Transmitting antenna is vertically polarized so receiver antenna must also be vertically polarized.

S4. Ans. (c)
Sol.

Therefore, (100)_10=(1100100)_2 .

S5. Ans.(d)
Sol. For any system to be dynamic it must have memory. Here, the output value of the independent variable at a given time depends only on the input at the same time , so the system is memoryless. Hence, the system is Non-dynamic.
The given equation has order greater than one so it cannot satisfy linearity property. Hence, the system is Non-linear.

S6. Ans.(c)
Sol. In a semiconductor charges will always have a tendency to move from higher concentrated area to less concentrated area to maintain equilibrium, this movement of charge carriers results in Diffusion current.

S7. Ans. (b)
Sol. By considering ω = 0 and ω = ∞, we can check the type of filter.

At ω = 0, inductor behaves as Short circuit and capacitor present in feedback behaves as open circuit so signal will pass through the circuit and we will get some output voltage.
At ω = ∞, inductor behaves as Open circuit and capacitor present in feedback behaves as Short circuit so due to open circuit inductor signal will not pass through the circuit and we will get no output voltage.

This is similar to the Low Pass Filter characteristics. So, The above figure behaves as a Low Pass Filter.

S8. Ans.(a)
Sol. Octal numbers can be made from binary numbers by grouping 3 consecutive binary digits starting from the right. For Example (101 100)2 = 542 .

S9. Ans.(d)
Sol. Passive network have no energy source of its own so they have no voltage or current sources. It depends on external source for operation.

S10. Ans.(d)

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