Electronics and Communication Engineering - Exam Questions Papers

26.
If the memory chip size is 256 x 1 bits, then the number of chips required to make up 1 kB (1024) bytes of memory is
32
24
12
8
Answer: Option
Explanation:

.


27.
A coil has a designed for high Q performance at a rated voltage and a specified frequency. If the frequency of operation is doubled, and the coil is operated at the same rated voltage, then the Q factor and the active power P consumed by the coil will be affected as follows.
P is doubled, Q is halved
P is halved, Q is doubled
P remains constant, Q is doubled
P decreases 4 times, Q is doubled
Answer: Option
Explanation:

ω2L = 2ω1L, R remains constant

Q2 = = 2Q1 i.e. Q is doubled

for a high a coil ωL >> R

i.e. P decreases 4 times.


28.
The number of variables in a function is odd and the number of minterms with even number of 0's are same as the number of minterms with odd number at 1 's, the expression formed can be represented in __________ as well as __________ form.
exclusive - OR, NOR
equivalence, exclusive - OR
AND, coincidence
OR, exclusive - OR
Answer: Option
Explanation:

With odd number of variables (n) terms with even number of 0's and terms with odd number of 1 's are the same.

Thus the k-map for the above condition with minterms represented by terms with even number of 0's is

for n = 3

The expression can be represented by equivalence (EX NOR) or (EX OR) expressions.


29.
Find the number of loop equation and number of possible trees for the given graph.
7, 2097152
7, 262144
7.5764801
6, 823543
Answer: Option
Explanation:

In any graph, Number of loop equations L = B - N + 1

where B = Number of branches, N = Number of nodes.

Given B = 14, N = 8

L = B - N + 1 = 7

The total number of trees possible

T = NN - 2 = 88 - 2 = 262144.


30.
The number of open right half plane poles of is
0
1
2
3
Answer: Option
Explanation:

Use Routh criteria.