IndiaBIX

Digital Electronics - Flip-Flops

Exercise : Flip-Flops - General Questions
56.
As a general rule for stable flip-flop triggering, the clock pulse rise and fall times must be:
very long.
very short.
at a maximum value to enable the input control signals to stabilize.
of no consequence as long as the levels are within the determinate range of value.
Answer: Option
Explanation:
No answer description is available. Let's discuss.
57.
A positive edge-triggered D flip-flop will store a 1 when ________.
the D input is HIGH and the clock transitions from HIGH to LOW
the D input is HIGH and the clock transitions from LOW to HIGH
the D input is HIGH and the clock is LOW
the D input is HIGH and the clock is HIGH
Answer: Option
Explanation:
No answer description is available. Let's discuss.
58.
If an input is activated by a signal transition, it is ________.
edge-triggered
toggle triggered
clock triggered
noise triggered
Answer: Option
Explanation:
No answer description is available. Let's discuss.
59.
A positive edge-triggered J-K flip-flop is used to produce a two-phase clock. However, when the circuit is operated it produces erratic results. Close examination with a scope reveals the presence of glitches. What causes the glitches, and how might the problem be corrected?
The PRESET and CLEAR terminals may have been left floating; they should be properly terminated if not being used.
The problem is caused by a race condition between the J and K inputs; an inverter should be inserted in one of the terminals to correct the problem.
A race condition exists between the Q and Q outputs to the AND gate; the AND gate should be replaced with a NAND gate.
A race condition exists between the clock and the outputs of the flip-flop feeding the AND gate; replace the flip-flop with a negative edge-triggered J-K Flip-Flop.
Answer: Option
Explanation:
No answer description is available. Let's discuss.
60.
A 555 operating as a monostable multivibrator has a C1 = 100 F. Determine R1 for a pulse width of 500 ms.
45
455
4.5 k
455 k
Answer: Option
Explanation:
No answer description is available. Let's discuss.
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers