Labour Officer • 2026 • Paper-III
Derive the S- Matrix of an ideal E-plane Tee.
Labour Officer • 2026 • Paper-III
The cutoff frequency of a waveguide depends on:
A)
Dimensions
B)
Material conductivity
C)
Operating power
D)
Noise figure
Correct option A: Dimensions
Labour Officer • 2026 • Paper-III
What is the difference between TE and TM modes in waveguides?
Labour Officer • 2026 • Paper-III
Explain the importance of microwave antennas in communication.
Labour Officer • 2026 • Paper-III
Calculate the transmission rate of TDM, if the link transmits 2000 frames per second, and each slot has 8 bits.
A)
64 Kbps
B)
16 Kbps
C)
8 Kbps
D)
32 Kbps
Correct option B: 16 Kbps
Labour Officer • 2026 • Paper-III
The information bit sequence {1 1 1 0 1 0 1 0 1} is to be transmitted by encoding with Cyclic Redundancy Check 4 (CRC-4) code, for which the generator polynomial is C(x) = x^4 + x + 1. What is the encoded sequence of bits?
Labour Officer • 2026 • Paper-III
Consider a discrete memoryless source with alphabet S = {s0, s1, s2, s3, s4, ...} and respective probabilities of occurrence P = {1/2, 1/4, 1/8, 1/16, 1/32, ...}. What is the entropy of the source (in bits)?
Labour Officer • 2026 • Paper-III
Radar range primarily depends on
A)
Peak transmitted power
B)
Average transmitted power
C)
Independent of transmitted power
D)
Distance between ends
Radar maximum range is primarily determined by the transmitted signal strength, especially the peak transmitted power. In the radar range equation, received power depends on transmitted peak power, so increasing peak power increases detection range. Average power is less important for pulsed radar range compared to peak power. 'Independent of transmitted power' is incorrect because range clearly varies with transmitted power. 'Distance between ends' is unrelated to radar range.
Labour Officer • 2026 • Paper-III
Define the term VSWR in microwave measurements.
Labour Officer • 2026 • Paper-III
Circular waveguides support:
A)
TE and TM modes
B)
TEM mode only
C)
TE mode only
D)
TM mode only
Correct option A: TE and TM modes
Labour Officer • 2026 • Paper-III
VSWR = 1 indicates:
A)
Perfect matching
B)
High mismatch
C)
Infinite reflection
D)
Zero transmission
Correct option A: Perfect matching
Labour Officer • 2026 • Paper-III
A directional coupler is used to:
A)
Sample a portion of power
B)
Amplify signals
C)
Convert frequency
D)
Reduce noise
Correct option A: Sample a portion of power
Labour Officer • 2026 • Paper-III
In 8086, the physical address is calculated as:
A)
Segment × 10H + Offset
B)
Segment + Offset
C)
Segment × 100H + Offset
D)
Segment – Offset
Correct option A: Segment × 10H + Offset
Labour Officer • 2026 • Paper-III
Which of the following devices cannot be used as a microwave oscillator?
A)
IMPATT diode
B)
TRAPATT diode
C)
PN Junction diode
D)
BARITT diode
Microwave oscillators are typically made using negative-resistance devices such as IMPATT, TRAPATT, and BARITT diodes. These devices can generate high-frequency microwave signals. A normal PN junction diode does not exhibit the required negative resistance or avalanche/transit-time behavior needed for microwave oscillation, so it cannot be used as a microwave oscillator.
Labour Officer • 2026 • Paper-III
Channel capacity increases with:
A)
Higher SNR
B)
Lower bandwidth
C)
Higher redundancy
D)
Lower entropy
Correct option A: Higher SNR
Labour Officer • 2026 • Paper-III
Magnetron is commonly used in:
A)
Radar systems
B)
Satellite communication
C)
Audio amplifiers
D)
Optical fiber
A magnetron is a high-power microwave oscillator. Its most common application is in radar systems, where it generates the microwave energy needed for transmitting pulses. It is not used for satellite communication (which typically uses klystrons, TWTs, or solid-state amplifiers), nor for audio amplifiers or optical fiber systems.
Labour Officer • 2026 • Paper-III
Power measurement at microwave frequencies uses:
A)
Bolometer
B)
Multimeter
C)
Oscilloscope
D)
Spectrum analyzer
Correct option A: Bolometer
Labour Officer • 2026 • Paper-III
I/O devices are connected to CPU through 16-bit
A)
Registers
B)
Buses
C)
ALU
D)
Control unit
Correct option B: Buses
Labour Officer • 2026 • Paper-III
A memory system has a total of 8 memory chips, each with 12 address lines and 4 data lines. The total size of the memory system is
A)
16 kbytes
B)
32 kbytes
C)
48 kbytes
D)
64 k bytes
Correct option A: 16 kbytes
Labour Officer • 2026 • Paper-III
What is the difference between computer architecture and computer organization?
Labour Officer • 2026 • Paper-III
Huffman coding is an example of:
A)
Lossless compression
B)
Lossy compression
C)
Error correction
D)
Modulation
Correct option A: Lossless compression
Labour Officer • 2026 • Paper-III
ASCII is used for:
A)
Image representation
B)
Text representation
C)
Audio representation
D)
Video representation
ASCII stands for American Standard Code for Information Interchange. It is a character encoding standard used to represent letters, digits, punctuation marks, and control characters in computers. Therefore, it is used for text representation. Image, audio, and video data are represented using different encoding formats, not ASCII.
Labour Officer • 2026 • Paper-III
In Pascal, begin and end are used to:
A)
Declare variables
B)
Mark program blocks
C)
Define loops
D)
End program
In Pascal, `begin` and `end` are block delimiters used to group multiple statements into a single program block. This is common in procedures, functions, loops, and conditional statements. They do not declare variables, define loops by themselves, or only end the entire program.
Labour Officer • 2026 • Paper-III
Slot antennas are commonly used in:
A)
Radar systems
B)
Audio broadcasting
C)
Optical communication
D)
HF radio
Correct option A: Radar systems
Labour Officer • 2026 • Paper-III
Frequencies in the UHF range propagate by means of
A)
space wave
B)
surface waves
C)
sky waves
D)
ground waves
Correct option A: space wave
