Electronics and Communication Engineering - Digital Electronics

6. 

In a 4 bit ripple counter using flip flops with tpd = 40 ns, the maximum frequency can be

A. 1.25 MHz
B. 3.25 MHz
C. 6.25 MHz
D. 12.5 MHz

Answer: Option C

Explanation:

Total time delay = 40 x 4 = 160 x 100-9s. Hence .


7. 

What will be FSV in 2 bit BCD D/A converter is a weighted resistor type with ER = 1V, R = 1 MΩ and Rf = 10KΩ

A. 0.99 V
B. 0.9 V
C. 0.1 V
D. 0

Answer: Option A

Explanation:

FSV for BCD = (10d - 1)VR. = (102 -1) x .


8. 

The number of product terms in the minimized sum of product expression obtained through the following K-map, where d, don't care.

A. 2
B. 3
C. 4
D. 5

Answer: Option A

Explanation:

y = B C + ACD.


9. 

BCD equivalent of - 810 is

A. 00110
B. 10110
C. 11000
D. 01000

Answer: Option C

Explanation:

Decimal 8 = 1000 and - 8 = 11000.


10. 

The number of inputs and outputs in a full adder are

A. 2 and 1
B. 2 and 2
C. 3 and 3
D. 3 and 2

Answer: Option D

Explanation: