Legal Metrology • Paper-III
A ROM is to be used to implement a “squarer”, which outputs the square of a 4-bit number. What must be the size of the ROM?
A)
8 address lines and 16 data lines
B)
4 address lines and 8 data lines
C)
8 address lines and 8 data lines
D)
4 address lines and 16 data lines
In the context of Electrical / Electronics Engineering, the most appropriate and technically accurate answer is '4 address lines and 16 data lines' (Option D).
Legal Metrology • Paper-III
The contents of Register (B) and Accumulator (A) of 8085 microprocessor are 49H and 3AH respectively. The contents of A and the status of carry flag (CY) and sign flag (S) after executing SUB B instruction are
A)
A=F1, CY=1, S=1
B)
A=0F, CY=1, S=1
C)
A=FO, CY =0, S=0
D)
A=1F, CY=1, S=1
3A−49H=F1H; subtraction requires a borrow so CY=1, and F1H has MSB 1 so S=1.
Legal Metrology • Paper-III
The resonant frequency of an RF amplifier is 1 MHz and its bandwidth is 10 KHz. The Q-factor will be
A)
0.01
B)
0.1
C)
10
D)
100
Q=f0/BW=1,000,000/10,000=100.
Legal Metrology • Paper-III
In a TV system, the modulation methods employed for video and audio signals are
A)
both amplitude modulation
B)
both frequency modulation
C)
respectively amplitude modulation and frequency modulation
D)
respectively frequency modulation and amplitude modulation
Analog TV traditionally uses AM for video and FM for audio.
Legal Metrology • Paper-III
Which of the following is a typical example of Time Division Multiplexing (TDM) application?
A)
AM radio broadcasting
B)
Cable television (CATV)
C)
Satellite communication
D)
DSL Internet access
In the context of Electrical / Electronics Engineering, the most appropriate and technically accurate answer is 'AM radio broadcasting' (Option A).
Legal Metrology • Paper-III
Consider a system consisting of a microprocessor, memory, and peripheral devices connected by a common bus. During DMA data transfer, the microprocessor
A)
only reads from the bus
B)
only writes to the bus
C)
both reads from and writes to the bus
D)
neither reads from nor writes to the bus
Option D is correct: neither reads from nor writes to the bus
Legal Metrology • Paper-III
In phase-shift SSB modulator, the input signals to one of the balanced modulators are phase-shifted by
A)
30°
B)
45°
C)
90°
D)
180°
In the context of Electrical / Electronics Engineering, the most appropriate and technically accurate answer is '90°' (Option C).
Legal Metrology • Paper-III
In a single-tone FM discriminator (S/N) is
A)
proportional to deviation
B)
proportional to cube of deviation
C)
inversely proportional to deviation
D)
proportional to square of deviation
For single-tone FM, the post-detection signal-to-noise improvement varies approximately with the square of frequency deviation.
Legal Metrology • Paper-III
Which of the following gives maximum probability of error?
A)
ASK
B)
FSK
C)
PSK
D)
DPSK
Amplitude Shift Keying (ASK) is highly susceptible to noise, giving it the maximum probability of error.
Legal Metrology • Electronics & Communication Engineering Paper-II
To construct a 512 K x 8 memory , the number of 32 K x 4 memory circuit required is
A)
16
B)
32
C)
8
D)
64
Number of chips = (Capacity needed) / (Capacity per chip) = (512K * 8) / (32K * 4) = 16 * 2 = 32.
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
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
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
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
Which of the transistor model is most preferred for the analysis of a transistor circuit both at mid-band and at high frequencies?
A)
h-parameter model
B)
y-parameter model
C)
s-parameter model
D)
Hybrid -2z model
In the context of Electrical / Electronics Engineering, the most appropriate and technically accurate answer is 's-parameter model' (Option C).
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
A parabolic dish antenna has a conical beam 2° wide. The directivity of the antenna is approximately
A)
20dB
B)
30dB
C)
40dB
D)
50dB
In the context of Unmapped / long tail, the most appropriate and technically accurate answer is '20dB' (Option A).
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
Find the approximate frequency of output waveform of a monostable multivibrator given that RC = 20x10⁻³ and feedback factor = 0.3.
A)
200Hz
B)
142Hz
C)
233Hz
D)
250Hz
For a monostable, T≈RC ln[1/(1−β)] = 0.02 ln(1/0.7)≈7.1 ms, giving about 140 Hz; B is the closest option.
Legal Metrology • Electronics & Communication Engineering Paper-II
A good current buffer has
A)
Low-input impedance and low-output impedance
B)
Low-input impedance and high-output impedance
C)
High-input impedance and low-output impedance
D)
High-input impedance and high-output impedance
In the context of Electrical / Electronics Engineering, the most appropriate and technically accurate answer is 'Low-input impedance and high-output impedance' (Option B).
Legal Metrology • Electronics & Communication Engineering Paper-II
The biasing circuit has a stability factor of 50. If due to temperature change, ICBO changes by 1 μA, then IC will change by
A)
100pA
B)
25pA
C)
20pA
D)
50μA
In the context of Electrical / Electronics Engineering, the most appropriate and technically accurate answer is '100pA' (Option A).
Legal Metrology • Electronics & Communication Engineering Paper-II
A differential amplifier has a transistor with β = 100, is biased at Ig = 0.48mA. Determine the value of CMRR and Av if R1 = 7.89kΩ and R2 = 5kΩ.
A)
49.54 Db
B)
49.65 dB
C)
49.77 dB
D)
49.60 dB
Using the given small-signal differential/common-mode relations gives a CMRR around 50 dB; B is the closest keyed value.
Legal Metrology • Electronics & Communication Engineering Paper-II
An antenna in free space receives 2W of power when the incident electric field is 20 mV/m rms. The effective aperture of the antenna is
A)
0.005 m²
B)
0.05 m²
C)
1.885 m²
D)
3.77 m²
In the context of Unmapped / long tail, the most appropriate and technically accurate answer is '3.77 m²' (Option D).
Legal Metrology • Electronics & Communication Engineering Paper-II
Which one of the following is not a closed loop system?
A)
Respiratory system of a human
B)
Thermostat
C)
Automatic pilot
D)
Toaster
A toaster typically operates on a timer (open loop) and does not adjust based on the toast's actual temperature.
