| 1 |
The impurity commonly used for realizing the
base region of a silicon n-p-n transistor is
|
| Options |
| A) Gallium |
B) Indium
|
| C) Boron |
D) Phosphorus |
|
|
|
| Correct Answer |
C |
|
| 2 |
Despite the presence of negative feedback,
control system still have problems of instability because the |
| Options |
| A) components used have nonlinearities. |
B) dynamic equations of the subsystems are not
known exactly. |
| C) mathematical analysis involves approximations. |
D) system has large negative phase angle at high
frequencies. |
|
|
|
| Correct Answer |
A |
|
| 3 |
The drain of an n-channel MOSFET is shorted to
the gate so that VGS = VDS. The threshold
voltage (VT) of MOSFET is 1 V. If the drain current (ID)
is 1 mA for VGS = 2V, then for VGS = 3V, ID
is |
| Options |
| A) 2 mA |
B) 3 mA |
| C) 9 mA |
D) 4 mA |
|
|
|
| Correct Answer |
D |
|
| 4 |
Let x(n) = (
)n u(n), y(n)=x2(n) and Y(ejw)
be the Fourier transform of y(n). Then Y(ej0) is |
| Options |
|
|
|
| Correct Answer |
A |
|
| 5 |
Noise with uniform power spectral density of N0W/Hz
is passed through a filter H (w) = 2
exp(-jwtd) followed by an
ideal low pass filter of bandwidth BHz. The output noise power in
Watts is
|
| Options |
| A) 2N0B |
B) 4N0B
|
| C) eN0B |
D) 16 N0B |
|
|
|
| Correct Answer |
B |
|
| 6 |
Consider the following statements S1 and S2
S1: At the resonant frequency the impedance of a series R-L-C
circuit is zero.
S2: In a parallel G-L-C circuit, increasing the conductance G
results in increase in its Q factor.
Which one of the following is correct?
|
| Options |
| A) S1 is FALSE and S2 is TRUE |
B) Both S1 and S2 are TRUE
|
| C) S1 is TRUE and S2 is FALSE |
D) Both S1 and S2 are FALSE |
|
|
|
| Correct Answer |
D |
|
| 7 |
A signal x(n) = sin(w0n
+ f ) is the input to a linear
time-invariant system having a frequency response H(e(jw ).
If the output of the system Ax(n – n0), then the most
general form of ÐH(ejw) will be |
| Options |
| A) - n0w0 + b
for any arbitrary real b. |
B) - n0w0 + 2pk
for any arbitrary integer k. |
| C) n0w0 + 2pk
for any arbitrary integer k. |
D) -n0w0 f . |
|
|
|
| Correct Answer |
B |
|
| 8 |
Consider a lossless antenna with a directive
gain of +6dB. If 1 mW of power is fed to it the total power radiated
by the antenna will be |
| Options |
| A) 4 mW |
B) 1 mW |
C)
7 mW |
D) 1/4 mW |
|
|
|
| Correct Answer |
A |
|
| 9 |
A MOS capacitor made using p type substrate is
in the accumulation mode. The dominant charge in the channel is due
to the presence of
|
| Options |
| A) holes |
B) electrons
|
| C) positively charged ions |
D) negatively charged ions |
|
|
|
| Correct Answer |
B |
|
| 10 |
Choose the correct one from among the alternatives A, B, C, D
after matching an item from Group 1 with the most appropriate item
in Group 2.
| Group1 |
Group 2 |
1: FM
2: DM
3: PSK
4: PCM |
P: Slope overload
Q: m -law
R: Envelope detector
S: Capture effect
T: Hilbert transform
U: Matched filter |
|
| Options |
| A) 1-T, 2-P, 3-U, 4-S |
B) 1-S, 2-U, 3-P,
4-T |
| C) 1-S, 2-P, 3-U,
4-Q |
D) 1-U, 2-R, 3-S,
4-Q |
|
|
|
| Correct Answer |
C |