Legal Metrology • Paper-I
A source is delivering maximum power to a resistance through a network. The ratio of power delivered to the source power
A)
is always 0.5
B)
may be 0.5 or less
C)
may be 0.5 or less or more
D)
maybe 0.5 or more
At maximum power transfer, efficiency is 50%, meaning the ratio of power delivered to the load vs source is 0.5.
Legal Metrology • Paper-I
Should real time instruments like oscilloscopes be time invariant?
A)
Yes
B)
Sometimes
C)
Never
D)
They have no relation with time variance
An ideal measuring instrument should be time-invariant so its characteristics do not change with time.
Legal Metrology • Paper-I
The analog signal m(t) is given below m(t) = 4 cos 100 πt + 8 sin 200 πt + cos 300 πt, the Nyquist sampling rate will be
A)
1/100
B)
1/200
C)
1/300
D)
1/600
The highest message frequency is 150 Hz because 300π rad/s =150 Hz, so the Nyquist rate is 300 Hz.
Legal Metrology • Paper-I
In a transistor
A)
I_E = I_B
B)
I_C = I_B
C)
I_E = I_C - I_B
D)
I_E = I_C + I_B
In the context of Unmapped / long tail, the most appropriate and technically accurate answer is 'I_E = I_C + I_B' (Option D).
Legal Metrology • Paper-I
Find the Z-transform of δ(n+3)
A)
z^3
B)
z^-3
C)
z
D)
z^-1
Z{δ(n+3)}=z³ under the standard bilateral Z-transform definition.
Legal Metrology • Paper-I
What is the ROC of z-transform of a two sided infinite sequence?
A)
|z| > r1
B)
|z| < r2
C)
r1 < |z| < r2
D)
|z| > 1
The ROC of a two-sided sequence is an annulus r1<|z|<r2.
Legal Metrology • Paper-I
A voltage wave having 5% fifth harmonic content is applied to a series RC circuit. The percentage fifth harmonic content in the current wave will be
A)
5%
B)
more than 5%
C)
less than 5%
D)
equal or more than 5%
In a series RC circuit, capacitive reactance decreases with frequency, so higher harmonics produce proportionally larger currents; fifth-harmonic percentage increases above 5%.
Legal Metrology • Paper-I
The minority carrier life time and diffusion constant in a semiconducting material are respectively 100 us and 100 cm2/s. The diffusion length of the carrier is
A)
0.7 cm
B)
0.01 cm
C)
0.0141 cm
D)
0.1 cm
In the context of Electrical / Electronics Engineering, the most appropriate and technically accurate answer is '0.7 cm' (Option A).
Legal Metrology • Electrical Engineering Paper-III
What is incorrect option for a reverse biased p-n junction diode
A)
the width of depletion layer increases
B)
the potential barrier is reduced
C)
the junction offers very high resistance
D)
no current flow in the circuit
In the context of Electrical / Electronics Engineering, the most appropriate and technically accurate answer is 'the width of depletion layer increases' (Option A).
Legal Metrology • Electrical Engineering Paper-III
When a trivalent impurity is added to a pure semiconductor it becomes
A)
an insulator
B)
an intrinsic semiconductor
C)
p-type semiconductor
D)
n-type semiconductor
Based on established principles in Electrical / Electronics Engineering, the correct and most clinically/technically appropriate choice is 'an intrinsic semiconductor' (Option B).
Legal Metrology • Electrical Engineering Paper-III
What kind of feedback circuit is called the emitter follower?
A)
voltage feedback
B)
current feedback
C)
both voltage and current feedback
D)
none of these
Based on established principles in this specific field of study, the correct and most clinically/technically appropriate choice is 'current feedback' (Option B).
Legal Metrology • Electrical Engineering Paper-III
An applied ac voltage to a full wave bridge rectifier is 50 V, what is the de output voltage?
A)
22.5V
B)
15.92 V
C)
45V
D)
S0V
In the context of Unmapped / long tail, the most appropriate and technically accurate answer is '15.92 V' (Option B).
Legal Metrology • Electrical Engineering Paper-III
What will be the current through 40 ohm resistor in the circuit shown below? Assume all diodes are ideal.
A)
3.75A
B)
2.5A
C)
5A
D)
3A
In the context of Electrical / Electronics Engineering, the most appropriate and technically accurate answer is '2.5A' (Option B).
Legal Metrology • Electrical Engineering Paper-III
The main difference between J-K and R-S flip-flop is that
A)
J-K flip flop does not need a clock pulse
B)
there is feedback in J-K flip-flop
C)
J-K flip-flop accepts both inputs as 1
D)
J-K flip-flop is acronym of junction cathode multivibrator
The J-K flip-flop removes the forbidden SR condition; with J=K=1 it toggles.
Legal Metrology • Electrical Engineering Paper-III
The microprocessor works on the principle of
A)
binary arithmetic
B)
decimal arithmetic
C)
both the decimal and binary arithmetic
D)
none of these
Based on established principles in Electrical / Electronics Engineering, the correct and most clinically/technically appropriate choice is 'binary arithmetic' (Option A).
Legal Metrology • Electrical Engineering Paper-III
The purpose of a coupling capacitor in a transistor amplifier is to
A)
protect the transistor
B)
pass ac-component and block dc-component
C)
increase the output impedance of transistor
D)
provide biasing
Based on established principles in this specific field of study, the correct and most clinically/technically appropriate choice is 'provide biasing' (Option D).
Legal Metrology • Electrical Engineering Paper-III
A zener diode is primarily used as
A)
an oscillator
B)
a rectifier
C)
an amplifier
D)
a voltage regulator
A Zener diode is operated in reverse breakdown to maintain an approximately constant voltage.
Legal Metrology • Electrical Engineering Paper-III
In a common base connection of npn-transistor, current amplification factor is 0.92. If the emitter current is 1.2 mA, what is the value of base current?
A)
1.104mA
B)
0.92mA
C)
0.096 mA
D)
0.092 mA
Based on established principles in this specific field of study, the correct and most clinically/technically appropriate choice is '0.92mA' (Option B).
Legal Metrology • Electrical Engineering Paper-III
Which one is not a transistor biasing method?
A)
base resistor method
B)
emitter bias method
C)
voltage-divider bias method
D)
current-divider bias method
Based on established principles in this specific field of study, the correct and most clinically/technically appropriate choice is 'emitter bias method' (Option B).
Legal Metrology • Electrical Engineering Paper-III
How many stages of amplification is/are required in a radio receiver?
A)
one stage
B)
two stages
C)
three stages
D)
more than three stages
Based on established principles in Electrical / Electronics Engineering, the correct and most clinically/technically appropriate choice is 'two stages' (Option B).
Legal Metrology • Electrical Engineering Paper-III
The relation between current gains α and β of a transistor is
A)
β = α / (1 - α)
B)
β = α / (1 + α)
C)
β = α / (1 - β)
D)
β = α
Based on established principles in this specific field of study, the correct and most clinically/technically appropriate choice is 'β = α / (1 + α)' (Option B).
Legal Metrology • Electrical Engineering Paper-II
As compare to Δ-Δ bank, the capacity of the V-V bank of transformers is
A)
57.7%
B)
66.7%
C)
50%
D)
86.6%
A V-V (open-delta) bank has 57.7% of the kVA capacity of an equivalent closed-delta bank.
Legal Metrology • Electrical Engineering Paper-II
Smaller the damping ratio
A)
keeps the time within limits
B)
larger is the rise time
C)
smaller is the rise time
D)
none of the above
A smaller damping ratio results in a faster initial response, which corresponds to a smaller rise time.
Legal Metrology • Electrical Engineering Paper-II
The value of demand factor of a power station is
A)
less than 1
B)
always zero
C)
greater than 1
D)
1.5
In the context of Electrical / Electronics Engineering, the most appropriate and technically accurate answer is 'less than 1' (Option A).
Legal Metrology • Electrical Engineering Paper-II
The transfer function of a system is 10 / (1+s). When operated as a unity feedback system, the steady-state error to a unit step input will be
A)
infinity
B)
10
C)
zero
D)
1/11
In the context of Electrical / Electronics Engineering, the most appropriate and technically accurate answer is 'zero' (Option C).
