Electronics and Communication Engineering - Digital Electronics

41. 

The number of distinct Boolean expression of 4 variables is

A. 16
B. 256
C. 1024
D. 65536

Answer: Option D

Explanation:

22n = 224 = 216 .


42. 

The fixed count that should be used so that the output register will represent the input for a 6 bit dual slope A/D converter uses a reference of -6v and a 1 MHz clock. It uses a fixed count of 40 (101000).

A. 000110
B. 0010
C. 1111
D. 011101

Answer: Option A

Explanation:

If is made to be unity, the O/P count N2 = ei, N1 = 6 = 000110.


43. 

For the K map in the given figure the simplified Boolean expression is

A. A C + A D + ABC
B. A C + A D + ABC
C. A C + A D + ACD
D. A C + A D + AB C

Answer: Option A

Explanation:


44. 

A memory system of size 16 k bytes is to be designed using memory chips which have 12 address lines and 4 data lines each. The number of such chips required to design the memory system is

A. 2
B. 4
C. 8
D. 18

Answer: Option C

Explanation:

.


45. 

In a 7 segment display, LEDs b and c lit up. The decimal number displayed is

A. 9
B. 7
C. 3
D. 1

Answer: Option D

Explanation: