# Quiz Electronics Engineering 28 July 2020

Quiz Electronics Engineering
Exam: NIC
Topic: Miscellaneous
Date: 28/07/2020

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

Q1. The most appropriate matching for the following pairs:
COLUMN-I COLUMN-II
Z: Auto decrement addressing 3. Constants
Options:
(a) X-3, Y-2, Z-1
(b) X-2, Y-3, Z-1
(c) X-3, Y-1, Z-2
(d) X-2, Y-1, Z-3

Q2. Consider the following statements regarding a plane wave propagating through free space: The direction of field is
1. ‘E’ is perpendicular to the direction of propagation
2. ‘H’ is perpendicular to the direction of propagation
3. ‘E’ is perpendicular to the direction of field ‘H’
Which of these statements are correct?
(a) 1 and 2
(b) 2 and 3
(c) 1 and 3
(d) 1, 2 and 3

Q3. A wire having resistance 100 Ω is bent in the form of a circle. The effective resistance between the two points on any diameter of the circle is
(a) 100 Ω
(b) 50 Ω
(c) Zero
(d) ∞

Q4. The Nyquist sampling frequency (in Hz) of a signal given by
6 × 104sin𝑐2(400𝑡)∗106sin𝑐3(100𝑡) is
(a) 200
(b) 300
(c) 1500
(d) 1000

Q5. The total circuit resistance of the given circuit is

(a) 440 Ω
(b) 110Ω
(c) Zero
(d) 1100 Ω

Q6. How many 128 x 8 bit RAMs are required to design 32K x 32 bit RAM
(a) 512
(b) 1024
(c) 128
(d) 32

Q7. Match List-I(Diode) with List-II(Application) and select the correct answer using codes given below the lists:
List-I
A. Varactor Diode
B. Tunnel Diode
C. Photo Diode
D. Zener Diode

List-II
1. to charge auxiliary storage batteries
2. Reference voltage
3. High frequency tuning circuit
4. High frequency switching circuit
Codes:
A B C D
(a) 2 1 4 3
(b) 3 1 4 2
(c) 2 4 1 3
(d) 3 4 1 2

Q8. What is the power of periodic non-sinusoidal voltage and currents?
(a) The sum of the root mean square power of the sinusoidal components including the fundamental
(b) The sum of the average powers of the harmonics excluding the fundamental
(c) The sum of the average powers of the sinusoidal components including the fundamental
(d) The average power of the fundamental components alone.

Q9. Which of the following is a digital device
(a) Regulator of a fan
(b) Microphone
(c) Resistance of a material
(d) Light switch

Q10. Electric field inside a hallow metallic charged sphere is
(a) Zero
(b) Decreasing towards centre
(c) Increasing toward centre
(d) None of these

SOLUTIONS

S1. Ans.(b)
Sol.
In Indirect addressing mode, the instruction points indirectly to the address of memory location where the data is stored or to be stored.
In Immediate addressing mode, the data is directly used in instruction itself.
In Autodecrement addressing mode the value in the base register is decremented by the size of the data item which is to be accessed. This step is done before determining the effective address within a loop.

S2. Ans.(d)

S10. Ans.(b)
Sol. Effective resistance between two points on any diameter of the circle is 50Ω.

S4. Ans.(b)
Sol. The given signal is 6 × 104sin𝑐2(400𝑡)∗106sin𝑐3(100𝑡)
Let two functions be
f1(t) = 104sin𝑐2(400𝑡)
f2(t) = 106sin𝑐3(100𝑡)
We know that Convolution in time domain is multiplication in frequency domain

Bandwidth of F1(ω) = 2 x 400 rad/sec = 800 rad/sec or 400 Hz [for sin𝑐2]
Bandwidth of F2(ω) = 3 x 100 rad/sec = 300 rad/sec or 150 Hz [for sin𝑐3]

The F1(ω).F2(ω) will have bandwidth of 150Hz only because in case of product of two spectrums we consider the minimum frequency.
So, Sampling frequency = 2 x 150 Hz = 300 Hz

S5. Ans.(a)
Sol. We know that,
P=V^2/R
⇒ P = V^2/P
⇒ R_1=(200)^2/1000=4Ω
⇒ R_2=(200)^2/100=400 Ω
So, the total resistance = R1 + R2 = 40 + 400 = 440 Ω.
S6. Ans.(b)
Sol.
Number of RAM’s = (32K x 32 bits)/(128 x 8 bits) = 210 = 1024

S7. Ans.(d)
Sol.
Zener Diode can be used as a Voltage regulator or as a reference voltage.
Varactor diode is widely used in high frequency tuning circuits like VCO and frequency modulators.
A Tunnel diode is a heavily doped p-n junction diode. It is used as a high frequency fast switching device.
Photo diode is used as an energy converter. It absorbs photons and convert them into electric current. It is used to charge auxiliary storage batteries.

S8. Ans.(a)

S9. Ans. (b)
Sol. An electric operating equipment have switch with two condition either ON or OFF, which is similar to that of digital switch conditions of 1 i.e., ON and 0 i.e., OFF. Rest have Fuzzy logic.

S10. Ans.(a)
Sol. Inside a hallow metallic charged sphere, electric field is always zero.

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