RRB JE ECE (CBT II) Mock Test- 7 - Electronics and Communication Engineering (ECE) MCQ

The Battle of Buxarwas fought on 22-23 October 1764 between the forces under the command of the British East India Company led by Hector Munro and the combined armies of Mir Qasim, Nawab of Bengal till 1763; the NawabAwadh; and the Mughal Emperor Shah Alam.

• The combined armies of Mughals, Awadh and MirQasim were defeated by the British army.
• Treaty of Allahabad was signed after the battle of Buxar.

The full form of LCD is Liquid Crystal Display.

• A liquid crystal display (LCD) is a thin, flat panel used for electronically displaying information such as text, images, and moving pictures
• It is an electronically-modulated optical device made up of any number of pixels filled with liquid crystals and arrayed in front of a light source (backlight) or reflector to produce images in color or monochrome

A point-to-point connection provides a dedicated link between two devices. The entire capacity of the link is reserved for transmission between those two devices. Most point-to-point connections use an actual length of wire or cable to connect the two ends, but other options, such as microwave or satellite links are also possible.

The effective of a data communications system depends on four fundamental characteristics:

delivery, accuracy. timeliness, and jitter.

• Delivery: The system must deliver data to the correct destination; Data must be received by the intended device or user
• Accuracy: The system must deliver the data accurately; Data that have been altered in transmission and left uncorrected are unusable
• Timeliness: The system must deliver data in a timely manner; Data delivered late are useless
• Jitter: Jitter refers to the variation in the packet arrival time; It is the uneven delay in the delivery of audio or video packets

The strength of an electromagnet can be increased by introducing a soft iron core inside the coil. We can make the electromagnet stronger by adding more turns to the coil.

In computing, the Trash (also known as the Recycle Bin in Windows) is the temporary storage for files that have been deleted in a file manager by the user, but not yet permanently erased from the file system.

Typically, a recycle bin is presented as a special file directory to the user, allowing the user to browse deleted files, undelete those that were deleted by mistake, or delete them permanently (either one by one, or by the "Empty Trash" function).

In Diamagnetic materials, a very weak form of magnetism that is non-permanent exists only while the external field is being applied

The relative permeability is small and less than unity

In paramagnetic materials, each atom possesses a permanent dipole moment by virtue of incomplete cancellation of electron spin and orbital magnetic moments

At the macroscopic level, these magnetic moments cancel out each other and there is no net magnetism in the absence of an electric field

as we know
αx² + βx + γ = 0
if C and D are roots of the above equation
C'D = γ/α
C + D = (-β/α)
Same can be applied for
(x + 5) (x + 7) - 8 = 0
x² + 12x + 27 = 0
the roots of above equation are a and b
ab = 27
a + b = -12
(x + a) (x + b) + 5 = 0
x² + x(a + b) + ab + 5 = 0
x² - 12x + 32 = 0
(x - 4) (x - 8) = 0
hence roots are 8 and 4

Oyilattam folk dance belongs to Madurai region of Tamil Nadu.

This dance is mainly performed at village festivals.

This dance highlights the epics of Ramayana and Mahabaratha.

Size:

8085 is 8-bit microprocessor

8086 is 16-bit microprocessor

Address Bus:

8085 has 16-bit address bus

8086 has 20-bit address bus

Memory:

8085 can access up to 64Kb

8086 can access up to 1 Mb of memory

Instruction:

8085 doesn’t have an instruction queue

8086 has an instruction queue

Pipelining:

8085 doesn’t support a pipelined architecture

8086 supports a pipelined architecture

I/O:

8085 can address 28 = 256 I/O's

8086 can access 216 = 65,536 I/O's.

Input function in C: scanf(), getchar() and fscanf()
Output functionin C: printf(), putchar() and fprintf()
Hence, the correct option is (C)

X = AB + ABC + AB̅C̅ + AC̅
X = AB (1 + C) + AC̅ + (B̅ + 1)
X = AB + AC̅
X = A(B + C̅)

Hence no. of gates required 3.
1 and
1 OR
1 NOT
Hence, the correct option is (C)

Inverse transducer is defined as a device which converts an electrical quantity into a non-electrical quantity.

A piezoelectric crystal acts as inverse transducer because when a voltage is applied across its surfaces, it changes its dimensions causing a mechanical displacement.
Hence, the correct option is (B)

Active transducers are those which do not require any power source for their operation. They produce an electrical signal proportional to the input.

Passive transducers require an external power and their output is a measure of some variation such as resistance, inductance, capacitance etc.
Hence, the correct option is (C)

• The electron beam in an oscilloscope can be deflected in two directions.
• One is horizontal (x-direction) and the second vertical (y-direction).
• When two inputs are applied at horizontal and vertical plates, two dimensional displays are produced as a result.

Hence, the correct option is (D)

The actual conversion of electrical to light energy takes place on the display screen when electrons strike a material known as a phosphor.

A phosphor is a chemical that glows when exposed to electrical energy. A commonly used phosphor is the compound zinc sulfide.

When pure zinc sulfide is struck by an electron beam, it gives off a greenish glow. The exact colour given off by a phosphor also depends on the presence of small amounts of impurities. For example, zinc sulfide with silver metal as an impurity gives off a bluish glow and with copper metal as an impurity, a greenish glow.

Ideal Op-amp has the following specifications i.e.

• R_in = ∞
• R_out = 0 Ω
• Gain A = ∞
• Slew rate = ∞
• CMRR = ∞
• Band width = ∞

• Traffic intensity is a measure of the average occupancy of a server or resource during a specified period, normally a busy hour
• It is measured in traffic units (erlangs) and defined as the ratio of the time during which a facility is cumulatively occupied to the time this facility is available for occupancy

An 8051 microcontroller is a mini computer in itself. It performs all the action of a computer on small scale. It has a CPU, memory (ROM/RAM) and I/O ports.

• A computer virus is a type of malicious software that, when executed, replicates itself by modifying other computer programs and inserting its own code
• When this replication succeeds, the affected areas are then said to be "infected" with a computer virus
• Michelangelo is the best-known computer virus 
• It is a boot sector virus; The only way you can get it is to boot your PC with an infected floppy disk

• In PCM an analogue signal is sampled and encoded into different levels before transmission
• The bandwidth of PCM depends on the number of levels
• If each sample is encoded into n bits, then the bandwidth of PCM is nf_s
• The bandwidth of DPCM is same as that of PCM signal, the only difference between PCM and DPCM is that the dynamic range is reduced in the DPCM signal
• However, in the case of Delta modulation, each sample is sent using only 1 bit which is +Δ or -Δ
• Hence there is bandwidth saving in Delta modulation

• Chelsea got the better of its English Premier League rivals to win the Europa League final Wednesday, beating Arsenal 4-1 in the Baku Olympic Stadium.
• Chelsea won their fifth major Uefa European competition final, with only Liverpool winning more among eight English clubs.

Digital personal assistant:

• A digital personal assistant is a software-based service that resides in the cloud, designed to help end users complete tasks online
• In 2015 Microsoft released Windows 10, which came with Cortana, a digital personal assistant like Apple’s Siri
• Alexa is a personal assistant developed by Amazon released in Nov 2017
• The Google Assistant is personal assistant developed by Google that is primarily available on mobile and smart home devices; It was first debuted in May 2016

To construct mod-m counter the number of flip flops required are given by:
n ≥ log₂m
Thus, for mod 64 counter, number of flip flops required are:
n ≥ log₂64
n = 6
mod- n means counter counts n states which are from 0 to n-1
Thus mod 64 counter counts from: 0 to 63
Largest decimal number: 63

Apply KCL at node A
10 = 2 + i
i = 8 A

Apply KVL
+60 (2) – 8 (10) – V = 0
120 – 80 = V
V = 40 V

A cell consists of a pair of metal strips called electrodes and dipped in a chemical solution called electrolyte.

Primary cells:

Primary cells are those which once fully used has to be thrown out or destroyed. This is because the electrodes and electrolyte used in this type of cells cannot be reused. Hence, primary cells are non-rechargeable cells.

Generally, the electrolyte used in primary cells is of paste form. Hence, these are called as dry cells. These are light in weight and have less cost.

Secondary cells:

Secondary cells are those which once used can be reused by charging them. Hence, secondary cells are rechargeable cells.

• UNCTAD is the principal organ of the UN General Assembly dealing with trade, investment, and development issues.
• The organization's goals are to  "maximize the trade, investment and development opportunities of developing countries and assist them in their efforts to integrate into the world economy on an equitable basis”.
• The headquarters of the United Nations Conference on Trade and Development is located in the Palace of Nations (United Nations Office at Geneva, Switzerland).

Step 1:

Find the binary representation of 21

Read the binary number form base:

21 in 2’s complement: 0001 0101

Step 2:

Find 1’s complement of 0001 0101

1’s complement of 0001 0101 is 1110 1010

Step 3:

Add 1 to find 2’s complement of the -21

1110 1010 + 1 = 1110 1011

∴ 2’s complement of -21 is 1110 1011

A scheme in which several channels are interleaved and then transmitted together is known as Frequency division multiplexing.

In Frequency division multiplexing signals occupy a range of frequency and two adjacent signals are separated by guard band to prevent mixing.

All the multiplexed signals are then transmitted simultaneously