Electronics and Communication Engineering - Exam Questions Papers

36. 

Consider the following statements a half adder.

  1. As a half subtractor also
  2. has two outputs CH = x x y and Sn = xy for two inputs x and y
  3. has two outputs CH = x + y and SH = xy for two inputs x and y
  4. is a combinational circuit
Which of the statements given above is/are correct?

A. 1, 3, 4
B. 1, 2, 4
C. 4 only
D. 2 and 3

Answer: Option B

Explanation:

Let two bit, verify S and B will same.


37. 

The expression given is F(A, B, C, D, E, F, G, H) = Σ(33, 48, 102, 158, 222, 229, 233, 243, 255); then the __________ and __________ minterms are grouped together into dual and variable __________ is reduced using the dual

A. 243, 233, D
B. 222, 158, B
C. 243, 255, A
D. 229, 243, E

Answer: Option B

Explanation:

We use Q-McCluskyey method of redaction

We can observe that minterms 158 and 222 can be grouped to reduce the variable 'B'.


38. 

If for certain x(t), the Fourier transform is:

Then for x(2t) the Fourier transform will be:

A.
B.
C.
D. same as X(jω)

Answer: Option A

Explanation:

Using scaling property

.


39. 

The circuit I in figure is

A. 1 mA
B. 4 mA
C. 8 mA
D. 10 mA

Answer: Option D

Explanation:

Current in the circuit is

[2 v at '+' terminal and '-' terminal will be same].


40. 

In x = the value of x is

A. 10
B. 25
C. 36
D. 44

Answer: Option D

Explanation:

= (10)2 + (10)3 + ... + (10)8 + (10)9

= (2)10 + (3)10 + .... + (8)10 + (9)10

= 2 + 3 + ... + 8 + 9 = 44.