Digital Circuits Flashcards
7 cards from real BEE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Digital Circuits flashcards as text
What is the purpose of a schmitt trigger in digital circuits?
Answer: To provide hysteresis for clean switching on noisy or slow-transition inputs
A Schmitt trigger uses two different threshold voltages (hysteresis) to produce a clean, bounce-free digital output from noisy or slowly changing input signals.
In which number system is the addition 1011 + 1101 performed, and what is the result?
Answer: Binary; result is 11000
1011₂ (11) + 1101₂ (13) = 11000₂ (24) in binary arithmetic.
Which type of ROM can be erased by exposing it to ultraviolet light?
Answer: EPROM
EPROM (Erasable Programmable ROM) is erased by UV light shone through its quartz window, resetting all cells to 1.
A synchronous 3-bit up counter is currently in state 110. What is the next state?
Answer: 111
110₂ = 6; the next count is 7 = 111₂ in a standard 3-bit synchronous up counter.
Which logic expression represents the output of an XNOR gate for inputs A and B?
Answer: A·B + Ā·B̄
XNOR outputs 1 when both inputs are the same: A·B (both 1) or Ā·B̄ (both 0), which is the complement of XOR.
What is the key advantage of synchronous circuits over asynchronous circuits?
Answer: Easier hazard-free design and predictable timing
Synchronous circuits clock all state changes to a common clock edge, making timing analysis, hazard avoidance, and design verification significantly simpler.
How many address lines are required to access each location in a 64K × 8 memory chip?
Answer: 16
64K = 2¹⁶ locations, so 16 address lines are needed to uniquely address each of the 65,536 memory locations.