EC GATE 2008 (Test 2)



Tag: ec gate 2008
Q.1
The two numbers represented in signed 2’s complement form are P + 11101101 and Q = 11100110. If Q is subtracted from P, the value obtained in signed 2’s complement is
A. 1000001111
B. 00000111
C. 11111001
D. 111111001
Answer : Option B
Explaination / Solution:



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Q.2
In the following circuit, the comparators output is logic “1” if V1 > V2 and is logic "0" otherwise. The D/A conversion is done as per the relationVolts, where b3 (MSB), b1,b2 and b0 (LSB) are the counter outputs. The counter starts from the clear state.

The stable reading of the LED displays is
A. 06
B. 07
C. 12
D. 13
Answer : Option D
Explaination / Solution:


and when VADC = 6.5 V (at 1101), the output of AND is zero and the counter stops. The stable output of LED display is 13.

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Q.3
In the following transistor circuit,  , and 𝛽 and all the capacitances are very large

The mid-band voltage gain of the amplifier is approximately
A. -180
B. -120
C. -90
D. -60
Answer : Option D
Explaination / Solution:

The small signal model is shown in fig below


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Q.4
A silicon wafer has 100 nm of oxide on it and is furnace at a temperature above 10000 C for further oxidation in dry oxygen. The oxidation rate
A. is independent of current oxide thickness and temperature
B. is independent of current oxide thickness but depends on temperature
C. slows down as the oxide grows
D. is zero as the existing oxide prevents further oxidation
Answer : Option D
Explaination / Solution:
No Explaination.


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Q.5
The OPAMP circuit shown above represents a

A. high pass filter
B. low pass filter
C. band pass filter
D. band reject filter
Answer : Option B
Explaination / Solution:

and from this equation it may be easily seen that this is the standard form of T.F. of low pass filter
and form this equation it may be easily seen that this is the standard form of T.F. of low pass filter



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Q.6
For a Hertz dipole antenna, the half power beam width (HPBW) in the E-plane is
A. 3600
B. 1800
C. 900
D. 450
Answer : Option C
Explaination / Solution:

The beam-width of Hertizian dipole is 1800 and its half power beam-width is 900

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Q.7
A signal flow graph of a system is given below

The set of equalities that corresponds to this signal flow graph is
A.
B.
C.
D.
Answer : Option C
Explaination / Solution:



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Q.8
Noise with double-sided power spectral density on K over all frequencies is passed through a RC low pass filter with 3 dB cut-off frequency of fc. The noise power at the filter output is
A. K
B. Kfc
C. kπfc
D.


Answer : Option C
Explaination / Solution:



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Q.9
A speed signal, band limited to 4 kHz and peak voltage varying between +5 V and -5 V, is sampled at the Nyquist rate. Each sample is quantized and represented by 8 bits. If the bits 0 and 1 are transmitted using bipolar pulses, the minimum bandwidth required for distortion free transmission is
A. 64 kHz
B. 32 kHz
C. 8 kHz
D. 4 kHz
Answer : Option B
Explaination / Solution:



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Q.10
The number of open right half plane of  is
A. 0
B. 1
C. 2
D. 3
Answer : Option C
Explaination / Solution:



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