Electronics and Communication Engineering - Electronic Devices and Circuits

26.
For the ring oscillator shown in the figure, the propagation delay of each inverter is 100 pico sec. What is the fundamental frequency of the oscillator output __________
10 MHz
100 MHz
1 GHz
2 GHz
Answer: Option
Explanation:

T = 500 x 10-12 = 5 x 10-10

= .


27.
If A is 1011, A" is
1011
0100
1100
1010
Answer: Option
Explanation:

Taking 2's complement twice gives the original number.


28.
Which of the following is not a characteristic of a flip flop?
It is a bistable device
It has two outputs
It has two outputs are complement of each other
It has one input terminal
Answer: Option
Explanation:

Flip-flop has more than 1 input.


29.
The number of flip flops needed for a Mod 7 counter are
7
5
3
1
Answer: Option
Explanation:

23 = 8 If 3 flip-flops are used the modulus can be a maximum of 8.


30.
For AB + A C + BC = AB + A C the dual form is
(A + B) (A + C)(B + C) = (A + B)(A + C)
(A + B ) (A + C)(B + C) = (A + B)(A + C)
(A + B) (A + C) (B + C) = (A + B) (A + C)
none of the above
Answer: Option
Explanation:

Change OR to AND and vice versa.