Electronics and Communication Engineering - Digital Electronics

36. 

A 4 bit down counter can count from

A. 0000 to 1111
B. 1111 to 0000
C. 000 to 111
D. 111 to 000

Answer: Option B

Explanation:

It can count from 15 to 0 or 1111 to 0000.


37. 

Assertion (A): In computers the data is stored in hexadecimal form

Reason (R): Hexadecimal representation is short as compared to binary representation.

A. Both A and R are correct and R is correct explanation of A
B. Both A and R are correct but R is not correct explanation of A
C. A is true, R is false
D. A is false, R is true

Answer: Option D

Explanation:

Data is stored in binary form only.


38. 

For the circuit of the given figure, the output equation is

A. Y = ABCD
B. Y = AB + CD
C. Y = A + BCD
D. Y = ABC + D

Answer: Option B

Explanation:

The inputs A and B are ANDed. Inputs B and C' so ANDed. The outputs of two AND gates are ORed.


39. 

Using 2's complement, the largest positive and negative number which can be stored with 8 bits are

A. +128 and -127
B. +128 and -128
C. +127 and -128
D. +127 and -127

Answer: Option C

Explanation:

Largest positive number is 0111 111 = + 127 and largest negative number is 1000 0000 = -128.


40. 

Three Mod-16 counters are connected in cascade. The maximum counting range is

A. 16
B. 256
C. 4096
D. none of the above

Answer: Option C

Explanation:

16 x 16 x 16 = 4096.