Electronics and Communication Engineering - Electronic Devices and Circuits

41.
As applied to a flip flop the word edge triggered's means
flip flop can change state when clock transition occurs
flip flop can change state when clock signal goes from LOW to HIGH only
flip flop can change state when clock signal goes from HIGH to LOW only
none of the above
Answer: Option
Explanation:

Edge triggering means the instant when clock transition occurs.


42.
A NOR gate is a combination of
OR gate and AND gate
AND gate and NOT gate
OR gate and NOT gate
two NOT gates
Answer: Option
Explanation:

OR and NOT = NOR.


43.
The 2's complement representation of - 17 is
01110
01111
11110
10001
Answer: Option
Explanation:

(17)10 = (10001)2 = (-17)10 = 1's complement of (17)2 + 1

the MSB is 0, hence (-17)2 cannot represented in 2's complement representation with 5 bit, therefore (-17) in 2's complement is simply (10001)2 = (17)10 .


44.
TTL inverter has
one input
two inputs
one or two inputs
three inputs
Answer: Option
Explanation:

Data input and control input.


45.
4 bit ripple counter and 4 bit synchronous counter are made using flip-flop having a propagation delay of 10 ns each. If the worst case delay in the ripple counter and the synchronous counter be R and S respectively, then
R = 10 ns, S = 40 ns
R = 40 ns, S = 10 ns
R = 10 ns, S = 30 ns
R = 30 ns, S = 10 ns
Answer: Option
Explanation:

In synchronous counter time delay is constant while in Ripple it is additive.