Legal Metrology • Electronics & Communication Engineering Paper-II
What is the role of emitter resistance in the transistor amplifying circuit?
A)
To prevent thermal runaway
B)
To prevent increase in gain
C)
To lower the output impedance
D)
To increase gain
In the context of Electrical / Electronics Engineering, the most appropriate and technically accurate answer is 'To prevent thermal runaway' (Option A).
Legal Metrology • Electronics & Communication Engineering Paper-II
A lossless transmission line having 50Ω characteristic impedance and length λ/4 is short circuited at one end and connected to an ideal voltage source of 1V at the other end. The current drawn from the voltage sources is
A)
0
B)
0.02A
C)
0.1A
D)
None of the these
In the context of Electrical / Electronics Engineering, the most appropriate and technically accurate answer is '0' (Option A).
Legal Metrology • Electronics & Communication Engineering Paper-II
What is the use of the compensation capacitor in op-amp?
A)
Improves the amplification of op-amp
B)
Decreases the slew rate of op-amp
C)
Increases the bandwidth of op-amp
D)
Op-amp acts as all pass filter
In the context of Electrical / Electronics Engineering, the most appropriate and technically accurate answer is 'Improves the amplification of op-amp' (Option A).
Legal Metrology • Electronics & Communication Engineering Paper-II
The unit of ∇ x H is
A)
Ampere
B)
Ampere/meter
C)
Ampere/meter²
D)
Ampere-meter
In the context of Electrical / Electronics Engineering, the most appropriate and technically accurate answer is 'Ampere/meter²' (Option C).
Legal Metrology • Electronics & Communication Engineering Paper-II
If the differential voltage gain and the common mode voltage gain of a differential amplifier are 48 dB and 2 dB respectively, then its common mode rejection ratio is
A)
23 dB
B)
25 dB
C)
46dB
D)
50dB
In the context of Electrical / Electronics Engineering, the most appropriate and technically accurate answer is '46dB' (Option C).
Legal Metrology • Electronics & Communication Engineering Paper-II
A 10 bit D/A converter given a maximum output of 10.23V. The resolution is
A)
10mV
B)
20mV
C)
15mV
D)
25mV
For a 10-bit DAC, one LSB is approximately 10.23/1024≈0.01 V = 10 mV.
Legal Metrology • Electronics & Communication Engineering Paper-II
For proper amplification by a transistor circuit, the operating point should be located at the ___ of the d.c. load line
A)
The end point E
B)
Middle
C)
The maximum current point
D)
None of the above
In the context of Electrical / Electronics Engineering, the most appropriate and technically accurate answer is 'The end point E' (Option A).
Legal Metrology • Electronics & Communication Engineering Paper-II
Which type of feedback is used by Hartley oscillator?
A)
Voltage series feedback
B)
Current series feedback
C)
Voltage shunt feedback
D)
Current shunt feedback
The Hartley oscillator uses voltage-series feedback.
Legal Metrology • Electronics & Communication Engineering Paper-II
Voltage series feedback (also called series shunt feed-back) results in
A)
Increase in both input and output impedance
B)
Decrease in both input and output impedance
C)
Increase in input impedance and decrease in output impedance
D)
Decrease in input impedance and increase in output impedance
In the context of Electrical / Electronics Engineering, the most appropriate and technically accurate answer is 'Decrease in input impedance and increase in output impedance' (Option D).
Legal Metrology • Electronics & Communication Engineering Paper-II
The circuit that will work as OR gate in positive level, will work as ___ gate in negative level logic.
A)
NOR gate
B)
NAND gate
C)
Both NAND and NOR gate
D)
AND gate
Positive-logic OR becomes negative-logic AND by Boolean duality.
Legal Metrology • Electronics & Communication Engineering Paper-II
Which one of the following is not correct Maxwell equation?
A)
∇ x E = -∂B/∂t
B)
∇ x H = J + ∂D/∂t
C)
∇ x D = ρ
D)
∇ x B = 0
In the context of Electrical / Electronics Engineering, the most appropriate and technically accurate answer is '∇ x B = 0' (Option D).
Legal Metrology • Electronics & Communication Engineering Paper-II
Distortion level in the output of RC phase shift network will be less than
A)
1%
B)
2%
C)
5%
D)
10%
RC phase-shift oscillators are known for low distortion; the standard MCQ answer is less than 5%.
Legal Metrology • Electronics & Communication Engineering Paper-II
For a transistor amplifier with self-biasing network, the following components are used: RE=4Ω, RC=4 kΩ, RB=4 kΩ and VCC=1 K. the appropriate value of the stability factor S will be
A)
4
B)
3
C)
2
D)
1.5
In the context of Electrical / Electronics Engineering, the most appropriate and technically accurate answer is '3' (Option B).
Legal Metrology • Electronics & Communication Engineering Paper-II
For a given sample-and-hold circuit, if the value of the hold capacitor is increased, then
A)
Droop rate decreases and acquisition time decreases
B)
Droop rate decreases and acquisition time increases
C)
Droop rate increases and acquisition time decreases
D)
Droop rate increases and acquisition time increases
A larger hold capacitor decreases the droop rate but takes longer to charge, increasing acquisition time.
Legal Metrology • Electronics & Communication Engineering Paper-II
A flip-flop is popularly known as
A)
Astable multivibrator
B)
Bistable multivibrator
C)
Monostable multivibrator
D)
None of these
A flip-flop is a bistable multivibrator because it has two stable states.
Legal Metrology • Electronics & Communication Engineering Paper-II
The ideal op-amp has the following characteristics
A)
Ri=∞, A=∞, Ro=0
B)
Ri=0, A=0, Ro=0
C)
Ri=∞, A=0, Ro=∞
D)
Ri=0, A=0, Ro=∞
In the context of Electrical / Electronics Engineering, the most appropriate and technically accurate answer is 'Ri=∞, A=0, Ro=∞' (Option C).
Legal Metrology • Electronics & Communication Engineering Paper-II
The highest noise margin is offered by
A)
TTL
B)
ECL
C)
IIL
D)
CMOS
CMOS has the largest typical noise margins among these logic families.
Legal Metrology • Paper-I
The longest wavelength that can be absorbed by silicon, which has the bandgap of 1.12 eV is 1.1 μm. If the longest wavelength that can be absorbed by another material is 0.87 μm, then the bandgap of this material is
A)
0.99 eV
B)
1.42 eV
C)
1.1 eV
D)
2.3 eV
Based on established principles in Electrical / Electronics Engineering, the correct and most clinically/technically appropriate choice is '2.3 eV' (Option D).
Legal Metrology • Paper-I
In the active region of a transistor, collector-base junction is biased.
A)
Forward, forward
B)
Reverse, reverse
C)
Reverse, forward
D)
Forward, reverse
In the context of Unmapped / long tail, the most appropriate and technically accurate answer is 'Forward, forward' (Option A).
Legal Metrology • Paper-I
In an n-type silicon crystal at room temperature, which of the following can have a concentration of 4 x 10^19 /cm3?
A)
Silicon atoms
B)
Holes
C)
Dopant atoms
D)
Valence electrons
Based on established principles in Electrical / Electronics Engineering, the correct and most clinically/technically appropriate choice is 'Silicon atoms' (Option A).
Legal Metrology • Paper-I
If a signal f(t) has energy E, the energy of the signal f(2t) is equal to
A)
E
B)
E/2
C)
2E
D)
4E
E_y=∫|f(2t)|²dt. With u=2t, E_y=E/2.
Legal Metrology • Paper-I
Digital ICs process
A)
Linear signals only
B)
Digital signals only
C)
Both linear and digital signals
D)
Continuous signals only
Digital ICs are designed to process discrete/digital logic signals.
Legal Metrology • Paper-I
A dielectric material must be
A)
Semiconductor
B)
Insulator
C)
Metal
D)
Resistor
In the context of Mechanical Engineering, the most appropriate and technically accurate answer is 'Insulator' (Option B).
Legal Metrology • Paper-I
Fourier transform of a signal h(t) is H(jω) = (2cos ω)(sin 2ω) / ω. The value of h(0) is
A)
1
B)
1/2
C)
1/4
D)
1/8
h(0)=(1/2π)∫H(jω)dω; using ∫sin(aω)/ω dω=π gives h(0)=1.
Legal Metrology • Paper-I
In fabrication Silicon BJT in ICs by epitaxial process, the number of diffusions used is usually
A)
9
B)
6
C)
2
D)
12
In the context of Unmapped / long tail, the most appropriate and technically accurate answer is '9' (Option A).
