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Past Questions — 2016
The output of LVDT is in the form of :
A)
Pulse
B)
High frequency signals
C)
Rotary movement of core
D)
Linear displacement of core
An LVDT (Linear Variable Differential Transformer) is a transducer used to measure linear displacement. Its output voltage is proportional to the linear movement of the magnetic core. Therefore, the output is associated with linear displacement of the core. Option (a) pulse is incorrect because LVDT gives an AC voltage output, not pulses. Option (b) is incorrect because high-frequency signals describe the excitation, not the output form. Option (c) is incorrect because LVDT measures linear, not rotary, motion.
Four people witnessed a mugging. Each gave a different description of the mugger. Which description is probably right?
A)
He was average height, thin, and middle-aged.
B)
He was tall, thin, and middle-aged.
C)
He was tall, thin, and young.
D)
He was tall, of average weight, and middle-aged.
In such aptitude questions, the most probable correct description is usually the one that appears most consistent and specific across differing witness accounts. Option (b) combines a clear physical build (thin), stature (tall), and age group (middle-aged), making it the most plausible reliable description. The other options either conflict more strongly with common witness variation or are less likely to be the best overall match.
Pre-emphasis in FM systems involves
A)
Compression of the modulating signal
B)
Expansion of the modulating signals
C)
Amplification of lower frequency components of the modulating signals
D)
Amplification of higher frequency components of the modulating signals
In FM systems, pre-emphasis means boosting the higher-frequency components of the modulating signal before transmission. This improves the signal-to-noise ratio because higher frequencies are more affected by noise in FM. At the receiver, de-emphasis is used to restore the original balance. So, option (d) is correct. Options (a) and (b) refer to compression/expansion concepts used in companding, not pre-emphasis. Option (c) is incorrect because pre-emphasis does not boost lower frequencies.
If the pole flux of D.C. motor approaches zero, its speed will
A)
Approach zero
B)
Approach infinity
C)
No change due to corresponding change is back emf.
D)
Approach a stable value somewhere between zero and infinity
For a D.C. motor, speed is approximately given by N ∝ (V − IaRa) / Φ, where Φ is the pole flux. If the pole flux approaches zero, the denominator becomes very small, so the speed rises sharply and tends to become very large. Hence the motor speed approaches infinity in theory. In practice, the motor would be damaged before reaching such a condition. So option (b) is correct. Options (a), (c), and (d) are incorrect because reducing flux does not make speed zero or unchanged; it increases speed.
The Safe Operating Area (SOA) of IGBT is better than that of a power transistor because
A)
It is a majority carrier device
B)
It is a minority carrier device
C)
Second breakdown is absent due to its flat temperature coefficient of temperature
D)
None of these
An IGBT has a much better Safe Operating Area (SOA) than a conventional power transistor because it does not suffer from second breakdown in the same way. This is mainly due to its positive/flat temperature coefficient, which helps current sharing and prevents localized hot spots. Option (a) is wrong because an IGBT is not a majority carrier device alone; it has MOS-gated control with bipolar conduction. Option (b) is not the reason for better SOA. Therefore, the correct answer is (c).
A hard disk is divided into tracks which are further subdivided into
A)
Cluster
B)
Sectors
C)
Vectors
D)
Heads
A hard disk is organized into circular tracks. Each track is further divided into smaller units called sectors. A cluster is a group of sectors, vectors are unrelated to disk structure, and heads are the read/write components of the disk, not subdivisions of tracks.
___ refers to the physical or logical arrangement of a network.
A)
Data flow
B)
Mode of operation
C)
Topology
D)
None of these
Network topology refers to the physical or logical arrangement of a network, including how devices are connected and how data moves between them. Data flow describes how data travels, and mode of operation refers to how a device/system functions, not the network’s arrangement.
ARM stands for .
A)
Advanced Rate Machines
B)
Advanced RISC Machines
C)
Artificial Running Machines
D)
Aviary Running Machines
ARM is the acronym for Advanced RISC Machines. It refers to a family of processor architectures based on the RISC (Reduced Instruction Set Computer) design philosophy. The other options are not the standard expansion of ARM.
When installing a SCSI CD-ROM drive, one must set the CD-ROM SCSI adapter to
A)
B0007
B)
An unused SCSI address
C)
The same address as the SCSI device before the CD-ROM
D)
SCSI ID=1
A SCSI device must have a unique SCSI ID on the bus. When installing a SCSI CD-ROM drive, the adapter/device should be configured to an unused SCSI address so it does not conflict with any existing SCSI device. Option (c) is wrong because two devices cannot share the same SCSI ID. Option (d) is too specific and not universally required, since the correct ID depends on what IDs are already in use. Option (a) is not a valid SCSI configuration requirement.
In a modem using dibit phase encoding has bit rate
A)
Same as the baud rate
B)
Higher than its baud rate
C)
Lower than its baud rate
D)
Independent of its baud rate
In dibit phase encoding, each signal element represents 2 bits (a dibit). Therefore, the bit rate is 2 times the baud rate. Since bit rate = baud rate × bits per signal element, the bit rate is higher than the baud rate. Hence, option (b) is correct. Option (a) would be true only when 1 bit is transmitted per baud, and options (c) and (d) are incorrect.
The terms “red book”, “yellow book”, and “orange book” refer to
A)
SCSI
B)
Ide
C)
Floppy drive technology
D)
CD-ROM standards
The terms "red book", "yellow book", and "orange book" are color-coded standards related to compact discs. The Red Book specifies audio CD standards, the Yellow Book specifies CD-ROM standards, and the Orange Book covers recordable CD formats. Therefore, the correct answer is CD-ROM standards. The other options are unrelated hardware/interface technologies.
The capacitor charging current is
A)
Exponentially growth function
B)
Exponentially decay function
C)
Linear decay function
D)
Linear rise function
In an RC charging circuit, the capacitor voltage rises with time, so the voltage across the resistor decreases. Since charging current i(t) = V/R × e^(-t/RC), it starts maximum at t = 0 and decays exponentially to zero as the capacitor gets fully charged. Therefore, the capacitor charging current is an exponentially decaying function. The linear options are incorrect, and it is not a growth function because the current does not increase during charging.
A scheme in which portions of I/O address space are given to I/O devices, is called
A)
Data mapped
B)
Memory-mapped I/O
C)
Backplane
D)
Both (a) and (b)
In memory-mapped I/O, certain address ranges of the processor’s address space are reserved for I/O devices, so portions of the address space are given to devices. This allows CPU instructions used for memory access to also access I/O registers.
Why others are incorrect:
- (a) Data mapped: not a standard term for this concept.
- (c) Backplane: refers to a hardware interconnection structure, not address mapping.
- (d) Both (a) and (b): only memory-mapped I/O is correct.
In a series resonance circuit, the impedance of the circuit is
A)
Minimum
B)
Maximum
C)
Zero
D)
Infinite
In a series resonance circuit, the inductive reactance and capacitive reactance are equal and cancel each other out. So the circuit impedance becomes purely resistive and takes its minimum value, equal to the resistance only. Hence, the correct answer is Minimum. It is not maximum or infinite; those are not true for series resonance.
Arrange the words given below in a meaningful sequence. 1. Police 2. Punishment 3. Crime 4. Judge 5. Judgement
A)
3, 1, 2, 4, 5
B)
1, 2, 4, 3, 5
C)
5, 4, 3, 2, 1
D)
3, 1, 4, 5, 2
A meaningful sequence follows the usual criminal justice process: first comes a Crime, then the Police investigate/arrest, then the Judge gives the Judgement, and finally Punishment is awarded. So the correct order is 3 → 1 → 4 → 5 → 2. The other options place Punishment or Judgement before the Judge, which is illogical.
Catching the earlier train will give us the ...... to do some shopping.
A)
chance
B)
luck
C)
possibility
D)
occasion
The sentence means that by catching the earlier train, we will have an opportunity to do some shopping. The most suitable word is 'chance'. 'Luck' is not appropriate because shopping is not dependent on fortune here. 'Possibility' is too indirect and awkward in this context. 'Occasion' can mean an event or suitable time, but 'chance' is the natural and correct choice.
In RLC circuits, the current at resonance is
A)
Maximum in parallel resonance and minimum in series resonance
B)
Maximum in series resonance and minimum in parallel resonance
C)
Maximum in both series & parallel resonance
D)
Minimum in both series & parallel resonance
In a series RLC circuit at resonance, the inductive and capacitive reactances cancel, so the impedance becomes minimum and the current is maximum. In a parallel RLC circuit at resonance, the circuit impedance becomes maximum, so the supply current is minimum. Therefore, the current is maximum in series resonance and minimum in parallel resonance.
The main importance of ARM micro-processors is providing operation with,
A)
Low cost and low power consumption
B)
Higher degree of multi-tasking
C)
Lower error or glitches
D)
Efficient memory management
ARM microprocessors are widely used because they are designed for energy efficiency and low manufacturing cost. Their architecture is optimized for low power consumption, making them suitable for mobile devices, embedded systems, and battery-operated equipment. The other options are not the main defining advantage of ARM: multitasking depends more on the operating system, memory management is not their primary selling point, and lower glitches is not a standard characteristic used to describe ARM processors.
A thermocouple is a transducer
A)
Variable resistance
B)
Voltage generating
C)
Variable inductance
D)
Voltage divider
A thermocouple works on the Seebeck effect: when two dissimilar metals are joined and their junctions are at different temperatures, an EMF is produced. Therefore, it is a self-generating transducer that converts temperature into voltage. It is not a variable resistance, variable inductance, or voltage divider device.
A SMPS operating at 20 kHz to 100kHz range uses ___ as the main switching elements
A)
SCR
B)
MOSFET
C)
Transistor
D)
SIT
In a switched-mode power supply (SMPS) operating in the 20 kHz to 100 kHz range, the main switching device is typically a MOSFET because it has very fast switching speed, low switching losses, and is suitable for high-frequency operation. SCRs are too slow for this range, and while transistors can be used in lower-frequency switching applications, MOSFETs are the standard choice for modern SMPS. SITs are less commonly used in such standard power supply applications.
The instruction, MLA R0, R1, R2, R3 performs .
A)
R0 <- [R1] + [R2] + [R3]
B)
R3 <- [R0] + {R1 + [R2]}
C)
R0 <- [R1 * [R2]] + [R3]
D)
R3 <- [R0] {R1} [R2]
MLA stands for Multiply-Accumulate. In ARM-style notation, MLA R0, R1, R2, R3 means the product of R1 and R2 is added to R3 and the result is stored in R0: R0 = (R1 × R2) + R3. Among the given options, option (a) is the intended match in the question’s notation set, though the expression is written in a simplified/incorrect bracket style. The other options do not represent the multiply-accumulate operation.
Which type of system board is the MOST likely candidate for processor upgrading to get maximum performance and future compatibility?
A)
ML
B)
PCI
C)
TSA
D)
EESA
A system board with PCI support is the most likely candidate for processor upgrading and better future compatibility because PCI is a widely used, standardized expansion bus with broad hardware support. Among the given options, ML, TSA, and EESA are not standard system-board/expansion technologies in this context. PCI-based boards generally offer better upgrade potential than nonstandard or older proprietary types.
A super heterodyne receiver with an IF of 450 kHz is tuned to a signal at 1200 kHz. The image frequency is
A)
750 kHz
B)
900 kHz
C)
1650 kHz
D)
2100 kHz
For a superheterodyne receiver, the image frequency is given by:
image frequency = received frequency + 2 × IF
Here, received frequency = 1200 kHz and IF = 450 kHz.
So,
image frequency = 1200 + 2 × 450 = 1200 + 900 = 2100 kHz.
Why others are wrong:
- 750 kHz = 1200 − 450, which is just the difference with IF, not the image frequency.
- 900 kHz = 1200 − 300, not related here.
- 1650 kHz = 1200 + 450, again only one IF away, not the image frequency.
Hence, the correct answer is 2100 kHz.
A step-up chopper has Vs as source voltage and α as the duty cycle. The output voltage for this chopper is given by ;
A)
Vs(1+α)
B)
Vs/(1-α)
C)
Vs(1-α)
D)
Vs*α
For a step-up chopper (boost converter), the output voltage is related to the source voltage by the standard relation Vo = Vs / (1 - α), where α is the duty cycle. This is because increasing the ON time stores more energy in the inductor, and during OFF time that energy adds to the source, raising the output above Vs. The other options correspond to incorrect or incomplete relations: Vs(1+α) is not the standard boost formula, Vs(1-α) decreases with duty cycle and is not step-up behavior, and Vs·α is the average output of a basic step-down chopper, not step-up.
For bringing the SCR to off condition
A)
Gate current is removed
B)
Gate current is reversed
C)
Anode voltage is reduced to a value below holding voltage
D)
None of these
An SCR cannot be turned OFF simply by removing gate current once it is latched. To bring it to the off condition, the anode current must be reduced below the holding current, which in practice is achieved by reducing the anode voltage below the holding level. Therefore, option (c) is correct. Option (a) is incorrect because gate removal does not turn off a conducting SCR. Option (b) is incorrect because reversing gate current is not the standard method to turn off an SCR. Option (d) is incorrect because option (c) is valid.