← Junior Engineer
Past Questions
HDMI is used to transmit —
A)
Video only
B)
Audio only
C)
Data only
D)
Both Video and Audio
HDMI carries both digital video and audio in one cable.
Which application is used for DTP?
A)
Adobe premiere
B)
PageMaker
C)
Cool edit
D)
Auto CAD
PageMaker (Aldus/Adobe) is classic Desktop Publishing software.
When computer cannot turn ON, what is the first thing we have to do-
A)
Check monitor
B)
Check Keyboard
C)
Check SMPS
D)
Check mouse
No power ON first check power supply unit - SMPS.
In computer Graphic card is also called —
A)
CPU
B)
ROM
C)
GPU
D)
RAM
Graphics card processor is called GPU - Graphics Processing Unit.
Which component connects storage devices like SSDs and HDDs to the motherboard?
A)
A RAM slot
B)
A SATA port
C)
An USB port
D)
SMPS
SATA port connects HDD/SSD storage devices to motherboard.
___ is a small but fast memory placed between the CPU and the main memory.
A)
USB
B)
Primary memory
C)
ROM
D)
Cache memory
Cache memory is small fast memory between CPU and main memory.
When we want to see registry, we press windows command and R and type —
A)
regedit
B)
msconfig
C)
registry
D)
ping
Run -> regedit opens Windows registry editor.
When we defragment a hard drive, what it does?
A)
Remove unwanted program
B)
Remove virus from all the drive which increase the speed
C)
Organize fragmented data for improved access speed
D)
Remove all unwanted hardware for ease of operating
Defragmentation reorganizes fragmented files contiguously for faster access.
What is the uses of PLC?
A)
To read input signal
B)
To perform computing
C)
To control devices like motor and light
D)
To store data
Main use is to control devices like motors, lights, actuators based on inputs.
What does the acronym IP stand for in networking?
A)
Internal program
B)
Integrated program
C)
International protocol
D)
Internet protocol
IP = Internet Protocol.
The current flowing in L and C at parallel resonance are —
A)
zero
B)
equal
C)
infinite
D)
different
At parallel resonance, IL = IC in magnitude, circulating between L and C, line current zero.
Which of the following is the central processing unit of PLC?
A)
I/O Module
B)
Processor
C)
Memory Unit
D)
Power Supply
The central processing unit (CPU) of a PLC is the Processor. It executes the control logic, processes input signals, and generates output commands, so it is the main computing unit of the PLC. The other options are not the CPU: the Memory Unit stores programs and data, the Power Supply provides operating power, and the I/O Module interfaces the PLC with field devices such as sensors and actuators.
Which of the following has the least wavelength?
A)
X-rays
B)
Ultra violet rays
C)
Infra-red
D)
UHF
Wavelength order: X-rays (~nm) < UV < IR < UHF; X-rays smallest.
Transformer is used to change the value of
A)
Voltage
B)
Frequency
C)
Power
D)
Power factor
Transformer changes voltage (and current) at same frequency, power nearly constant.
In arm processor L1 cache is —
A)
Smallest and fastest
B)
Largest and fastest
C)
Largest and slowest
D)
Same as the other Cache
L1 cache is smallest and fastest, closest to core.
Which of the following is not correct?
A)
Voltage source is an active element
B)
Current source is a passive element
C)
Resistance is a passive element
D)
Conductance is a passive element
Option D is correct: Conductance is a passive element.
Source transformation technique is mainly based on law.
A)
Newton’s
B)
Kirchhoff’s
C)
Ohm’s
D)
Einstein’s
Source transformation (voltage to current) uses Ohm's law V=IR.
A volt meter has an accuracy of ± 3% of full scale 250 V range is employed to read 150V. The actual voltage value will fall within the range —
A)
140.5 to 150.5 V
B)
143 to 150 V
C)
142.5 to 157.5 V
D)
147 to 153
The voltmeter accuracy is ±3% of full scale, and the full-scale range is 250 V. So the maximum absolute error is ±(3/100 × 250) = ±7.5 V. If the meter reads 150 V, the actual voltage can be anywhere from 150 − 7.5 = 142.5 V to 150 + 7.5 = 157.5 V. Therefore, the correct range is 142.5 to 157.5 V, which is option c.
Why the other options are incorrect:
- a (140.5 to 150.5 V): This uses a much smaller error band and does not match ±3% of full scale.
- b (143 to 150 V): This is not a symmetric tolerance around 150 V and underestimates the possible upper value.
- d (147 to 153): This corresponds to only ±3 V, which is not the correct error from a 250 V full-scale meter.
Note: The correct option is c, not d.
Two equal sized transformers A and B are connected in parallel. The impedance of A is more than the impedance of B. Then~
A)
both will share the load equally
B)
A will supply more load than B
C)
B will supply more load than A
D)
load supply is not effected
When two equal-sized transformers are connected in parallel, the load current divides inversely proportional to their impedances. Since transformer A has higher impedance than transformer B, A will carry less current and B will carry more current. Therefore, B will supply more load than A.
Why others are incorrect:
- a) Both will share the load equally: This is only true if their impedances are equal.
- b) A will supply more load than B: Incorrect because higher impedance means lower current share.
- d) Load supply is not effected: Incorrect; the load sharing is definitely affected by the difference in impedance.
Turn off time of an SCR is measured from the instant —
A)
anode current becomes zero
B)
anode voltage becomes zero
C)
gate current becomes zero
D)
anode voltage and anode current becomes zero at the same time
Turn-off time measured from anode current zero to recovery of blocking capability.
A thyristor can be termed as—
A)
DC Switch
B)
AC Switch
C)
Square wave switch
D)
Both (a) & (b) are correct
SCR thyristor can switch both DC and AC (with commutation), so considered both AC and DC switch.
In single phase full converter, the output voltage during overlap is equal to-
A)
Zero
B)
Source voltage
C)
Source voltage minus the inductance drop
D)
Load voltage
During overlap due to source inductance, output is shorted, voltage is zero.
Choppers converter —
A)
AC to DC
B)
DC to AC
C)
DC to DC
D)
AC to AC
Chopper converts fixed DC to variable DC (DC-DC).
Hysteresis in an instrument means —
A)
the reliability of the instrument
B)
the repeatability of the instrument
C)
the change in the same reading when the input is first increased and then decreased
D)
the inaccuracy due to change in temperature
Hysteresis in an instrument is the phenomenon where, for the same value of input, the instrument gives different readings depending on whether the input is approached by increasing or decreasing it. In other words, the output depends on the previous history of the input. Option (c) states this correctly: the reading changes when the input is first increased and then decreased.
Why the others are wrong:
- (b) Repeatability means the ability of an instrument to give the same reading for repeated measurements under identical conditions; it is not hysteresis.
- (d) Inaccuracy due to change in temperature refers to temperature error, not hysteresis.
- (a) Reliability means the likelihood that an instrument performs consistently without failure; it is unrelated to hysteresis.
What is the benefit of arm processor in embedded system?
A)
Can control everything
B)
Low power consumption
C)
Easy to program
D)
Task manager
ARM processors offer low power consumption ideal for embedded systems.