Electronics and Communication Engineering - Digital Electronics

31. 

The dual of A + [B + (AC)] + D is

A. A + [(B (A + C))] + D
B. A [B + AC] D
C. A + [B (A + C)] D
D. A [B (A + C)] D

Answer: Option D

Explanation:

In taking dual OR is replaced by AND and vice versa.


32. 

A divide by 78 counter can be obtained by

A. 6 numbers of mod-13 counters
B. 13 numbers of mod-6 counters
C. one mod-13 counter followed by mod-6 counter
D. 13 number of mod-13 counters

Answer: Option C

Explanation:

Modulus 13 x modulus 6 = modulus 78.


33. 

The initial state of MOD-16 down counter is 0110. What state will it be after 37 clock pulses?

A. Indeterminate
B. 0110
C. 0101
D. 0001

Answer: Option D

Explanation:

A mod-16 counter goes through 16 states in one cycle of 16 Pulses.

It complete 2 cycles in 32 Pulses.

In the rest 5 Pulses, it moves down from 0110 = 610 - 510 = 110 or (001)2 .


34. 

The number of address lines in EPROM 4096 x 8 is

A. 2
B. 4
C. 8
D. 12

Answer: Option D

Explanation:

212 = 4096.


35. 

If the inputs to a 3 bit binary adder are 1112 and 1112, the output will be 1102

A. True
B. False

Answer: Option B

Explanation:

111 + 111 = 1110.