EC GATE 2009 - Online Test
Q1. The amplitude of a random signal is uniformly distributed between -5 V and 5 V.If the signal to quantization noise ratio required in uniformly quantizing the signal is 43.5 dB, the step of the quantization is approximately
Answer : Option C
Explaination / Solution:
Q2. The Fourier series of a real periodic function has only (P) cosine terms if it is even (Q) sine terms if it is even (R) cosine terms if it is odd (S) sine terms if it is odd Which of the above statements are correct ?
Answer : Option A
Explaination / Solution:
The Fourier series of a real periodic function has only cosine terms if it is even and sine terms if it is odd.
Q3. The ROC of z -transform of the discrete time sequence 
Answer : Option A
Explaination / Solution:
Taking z transform we have
Taking z transform we have
Q4. 
In the circuit shown below, the op-amp is ideal, the transistor has VBE = 0.6 V and β= 150. Decide whether the feedback in the circuit is positive or negative and determine the voltage V at the output of the op-amp.
Answer : Option D
Explaination / Solution:
The circuit is shown in fig below
Q5. If X = 1 in logic equation 
Then
Then
Answer : Option D
Explaination / Solution:
Substituting X = 1 and
we get
1 + A = 1 and 0 + A = A
Substituting X = 1 and
we get 1 + A = 1 and 0 + A = A
Q6. What are the minimum number of 2- to -1 multiplexers required to generate a 2- input AND gate and a 2- input Ex-OR gate
Answer : Option A
Explaination / Solution:
The AND gate implementation by 2:1 mux is as follows
Q7. 
In the interconnection of ideal sources shown in the figure, it is known that the 60 V source is absorbing power.
Which of the following can be the value of the current source I ?
Answer : Option A
Explaination / Solution:
Circuit is as shown below
Since 60 V source is absorbing power. So, in 60 V source current flows from + to - ve direction So,
I + I1 = 12
I = 12 - I1
I is always less then 12 A So, only option (A) satisfies this conditions.
Q8. If the transfer function of the following network is
Answer : Option C
Explaination / Solution:
Q9. What are the counting states (Q1,Q2) for the counter shown in the figure below
Answer : Option A
Explaination / Solution:
The given circuit is as follows.
The truth table is as shown below. Sequence is 00, 11, 10, 00 ...
The truth table is as shown below. Sequence is 00, 11, 10, 00 ...
Q10.
If segments a to g are considered as functions of P1 and P2, then which of the following is correct
Answer : Option B
Explaination / Solution:
LED d is 1 all condition and also it depends on
d = c + e
