| Post Name | JUNIOR INSTRUCTOR (ELECTRONICS MECHANIC) - Industrial Training |
|---|---|
| Question Paper Code | 168/2024 |
| Category Code | 656/2023 |
| Date of Test | 28 November 2024 |
| Medium of Question | ENGLISH |
| Exam Type | OMR Examination |
| Total Questions | 100 |
1
Unit of specific resistance is :
Answer
B. Ω –m
2
The value of temperature co-efficient of resistance depends upon :
(i) Nature of the material and temperature
(ii) Nature of the material and length of the material
(iii) Length of the material and volume of the material
(iv) Nature of the material and volume of the material
Answer
C. Only (i)
3
In resistor colour coding if the third band is gold, it represents a multiplying factor of :
Answer
B. 0.1
4
Combined or equivalent resistance of a parallel circuit is :
Answer
A. Less than the least amongst them
5
Ceramic capacitor has a approximate capacitance range of :
Answer
Question Cancelled
6
Five equal capacitors connected in series have a resultant of 4 μF. When these connected
in parallel and charged to 400 Vdc supply. Then the total energy stored is :
Answer
D. 8J
7
Two coils each having an inductance of 250 μH have combined inductance of 550 μH
when connected series aiding and 450 μH when connected series opposing. Find the
mutual inductance :
Answer
C. 25 μH
8
A coil has a resistance of 30 Ω and an inductance of 127.3 mH. It is connected across a
200 V, 50 Hz supply. Find impedance :
Answer
B. 50 Ω
9
A transformer is an efficient device because it :
Answer
D. Is a static device
10
What is the approximate efficiency of large transformers?
Answer
A. 95%
11
In Silver Oxide cell, the anode is made up of :
Answer
C. Zinc in an alkaline electrolyte
12
In half wave rectifier DC output voltage in terms of VS(rms) :
Answer
A. 0.45 Vs(rms)
13
A device whose characteristics are very close to that of an ideal voltage source is
Answer
D. Zener diode
14
Which of the following is a switching voltage regulator?
Answer
C. 78S40
15
Inverter is a device that :
Answer
D. converts dc power into ac power
16
The resistance of voltmeter is usually
Answer
D. High
17
Unit of susceptibility is
Answer
D. No units
18
Range extension of Ammeter requires —————— with milli ammeter
Answer
A. A shunt resistor
19
Norton’s theorem is —————— form of an equivalent circuit
Answer
B. Current
20
Air friction damping is used in the instrument which is
Answer
A. Moving iron
21
In an R – L – C circuit, the phase of the current with respect to the circuit voltage will be
Answer
D. Depends up on the value of L and C
22
Which of the following are used to increase the range of ammeters?
Answer
B. Shunts
23
The power in a pure inductive circuit is
Answer
A. Zero
24
When ac voltage is connected to a PMMC meter, then
Answer
B. The reading is zero
25
Value of current at resonance in a series RLC circuit is affected by the value of:
Answer
C. apacitance)
26
The time base signal in a CRO is:
Answer
C. A sawtooth signal
27
Ohm’s law is not applicable to:
Answer
D. Semi conductors
28
The source of electron beam in a CRO is:
Answer
A. Electron gun
29
Which one has negative temperature co-efficient of resistance?
Answer
B. Carbon
30
The internal resistance of an ammeter should be:
Answer
A. Very small
31
According to Krichoff’s first law current at a junction is:
Answer
D. Zero
32
Dual beam oscilloscope has:
Answer
C. Two electron guns
33
The “Superposition theorem” is essentially based on the concept of :
Answer
B. Linearity
34
The signal to be observed on the screen of an oscilloscope is applied for:
Answer
A. Across its vertical plates
35
The current carrying capacity of a copper wire having twice the diameter of another
copper wire is:
Answer
C. Four times as great
36
In a CRO ‘X’ axis normally represents:
Answer
A. Time
37
Moving Iron instruments have —————— scale.
Answer
Question Cancelled
38
The diode when reverse biased, the current flowing through it due to the minority
carriers is called :
Answer
Question Cancelled
39
An astable multivibrator using IC 555 has R_A = 72 kΩ, R_B = 36 kΩ and C = 10 μF. What is the frequency of oscillation?
Answer
C. 1 Hz
40
The GBP of an OP-AMP is specified as 1 MHz What is the maximum gain that can be
obtained using this Op-Amp at 1 kHz :
Answer
C. 1000
41
Transistor test with ohm meter base to collector and emitter in forward bias and reverse
bias condition show low resistance so transistor is :
Answer
C. Short
42
What is the output resistance of common collector configuration of amplifier?
Answer
A. Less than 100 Ω
43
Current gain of a common emitter amplifier is :
Answer
D. Ic/Ib
44
In crystal oscillator the crystal also convert electrical energy into ––––––––––– energy.
Answer
C. Mechanical energy
45
Which transistor amplifier has an efficiency of about 85%?
Answer
C. Class-C
46
According to barkhausen, loop gain is :
Answer
A. Aβ = 1
47
The frequency of oscillations in Wein bridge oscillator is :
Answer
C. f = 1/(2πRC)
48
The output of an oscillator may be square, triangular or saw tooth wave form, it is
known as :
(i) Sinusoidal oscillators
(ii) Non sinusoidal oscillators
(iii) Relaxation oscillators
Answer
C. Only (ii) and (iii)
49
Clipper circuit has grate application in :
(i) Radars
(ii) Digital Computers
(iii) Radio Receivers
Answer
Question Cancelled
50
Pin No 1 of IC LM 741 is :
Answer
D. Offset null
51
Class B operation of amplifier, one in which the device current flows over :
Answer
A. Half cycle
52
The maximum power of a 555 IC can dissipate is around :
Answer
B. 600 mW
53
IGBT has :
Answer
A. High input impedance and large bipolar current carrying capability
54
An IGBT is driven by :
Answer
C. Gate voltage
55
Minimum amount of emitter current to place the UJT in negative resistance region is
known as :
Answer
B. Peak point current
56
Typical value of intrinsic stand off ratio of UJT vary from :
Answer
D. 0.5 to 0.8
57
The insulating layer of MOSFET is :
Answer
B. Silicon dioxide
58
In JFET,
Answer
A. the voltage at the gate controls the main current
59
For the biasing of JFET,
Answer
C. gate always reverse biased
60
The maximum drain current (Id) of BFW 10 JFET is,
Answer
D. 20 mA
61
The current through the SCR can be turned off :
Answer
A. only by reducing the load current below the holding current
62
The terminals of TRIAC,
Answer
C. Main terminal 1, Main terminal 2, Gate
63
Which of the following is a TRIAC?
Answer
B. BT 136
64
The DIAC acts in a similar manner to,
Answer
D. two diodes connected in reverse parallel
168/2024 12 A
65
Ratio between minimum fusing current and current rating is termed as :
Answer
C. Fusing factor
66
Which type of MCB is designed to protect circuits with inductive load?
Answer
B. G series MCB
67
What is the full form of abbreviation ELCB used in electrical circuits?
Answer
C. Earth Leakage Circuit Breaker
68
A device which opens or closes an auxiliary circuit under predetermined condition in the
main circuit?
Answer
D. Relay
69
Which type of DC motor has 2 field coils, one is connected in series with the armature
and the other is connected parallel with the armature?
Answer
C. Compound motor
70
For 100% AM modulation calculate the power transmitted by carrier signal if total power
is 6000 W :
Answer
C. 4000 W
71
In Radio frequency spectrum Very Low Frequency (VLF) ranges from :
Answer
B. 3 – 30 kHz
72
An Omnidirectional antenna is designed to provide –––––––––– radiation pattern.
Answer
D. 360°
73
Which of the following characteristics changes in Frequency Modulation?
Answer
A. Carrier Wave frequency
74
According to Nyquist criteria of sampling theorem the sampling frequency is :
Answer
B. Twice the signal frequency
75
Which among the following is a digital modulation technique?
Answer
D. ASK
76
Which of the following device interconnects two separate electrical circuits by means of
light sensitive optical interface?
Answer
C. Optocoupler
77
The geographical area under one base station with a single transmitter and a receiver is
known as :
Answer
A. Cell
78
Which wireless technology link is used for mobile phone data transfer?
Answer
C. Bluetooth
79
The core of Optical fiber is made of :
Answer
A. Silica or Glass
80
The process of joining two ends of optical fiber using electric or mechanic means is :
Answer
B. Splicing
81
Which among the following is not an advantage of Geosynchronous satellite?
Answer
B. No coverage in polar region
82
The combination of Receiver, Amplifier and Transmitter in Satellite communication is
known as :
Answer
D. Transponder
83
If the number 25 in the radix x number system is equivalent to 15 in decimal, what is
the value of x?
Answer
Question Cancelled
84
Which of the following statements is correct?
Answer
D. Decimal 10 is represented as 1111 in Gray code
A 15 168/2024
85
The simplified form of the logic expression AB + A B + AB + A
Answer
A. 1
86
An OR gate with 2 inputs is followed by a NOR gate, where one input of the NOR gate is
grounded. If inputs to the OR gate are A = 1 and B = 0 , what will be the final output of
the circuit?
Answer
A. 0
87
How many select inputs are required for 1:32 demultiplexer?
Answer
C. 5
88
How many 2-to-4-line decoders are required to implement a 4-to-16-line decoder?
Answer
D. 5
89
A 2 input XOR gate can be implemented using a 2:1 multiplexer by :
Answer
B. Connecting one input to the select line, the second input to one data input
and the complement of the second input to the other data input
90
In a D flipflop, the complement of output is fed back to input. If the clock frequency is
30 Hz, what will be the frequency of the output?
Answer
C. 15 Hz
91
The waveforms of a counter are show in the figure below. This is
Answer
B. 3-bit ripple counter
92
In a 4-bit ripple counter, if the time period of the input clock pulse is 16 μs, what is the
time period of output wave at the most significant bit?
Answer
D. 256 μs
93
What is the ROM address space for an 8051 with 8 KB of on chip ROM?
Answer
A. 0000H to 1FFFH
94
What is the behaviour of the reset pin in the 8051 microcontroller?
Answer
C. The reset pin is active high and requires a high pulse to be activated
95
Match the following addressing modes with their corresponding 8051 Instructions
(1) Register (i) MOV R5, #25H
(2) Direct (ii) ADD A, R7
(3) Immediate (iii) MOV A,
Answer
D. (1)-(ii), (2)-(iv), (3)-(i), (4)-(iii)
A 17 168/2024
96
Which of the following is an example of a passive transducer?
Answer
D. Strain gauge
97
Which characteristic of a thermistor makes it extremely suitable for precision
temperature control systems?
Answer
B. High resistance variation with temperature
98
Which of the following is not an advantage of LVDT?
Answer
B. High hysteresis
99
In an inductive transducer, increasing the reluctance of the core will
Answer
A. Decrease the inductance
100
The current flow that occurs when two dissimilar conductors are joined to form a
thermocouple is primarily due to which effect?
Answer
B. See beck effect
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