Multivibrators and 555 Timer Questions and Answers

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Showing 10 of 45 questions
Q31
The 74S124 TTL chip is a voltage-controlled oscillator that will generate a specific frequency at Vout.
  • A TRUE
  • B FALSE
Answer: Option B
Q32
A single Schmitt trigger inverter is all that is needed to build a simple astable multivibrator.
  • A TRUE
  • B FALSE
Answer: Option B
Q33
The bistable multivibrator is an R-C flip-flop.
  • A TRUE
  • B FALSE
Answer: Option B
Q34
When the 74123, a retriggerable monostable multivibrator device, ends its timing cycle it must be started all over again.
  • A TRUE
  • B FALSE
Answer: Option B
Q35
A multivibrator is a circuit that changes between two digital levels on a continuous, free-running basis or on demand.
  • A TRUE
  • B FALSE
Answer: Option A
Q36
A monostable multivibrator is commonly called a two shot.
  • A TRUE
  • B FALSE
Answer: Option B
Q37
On the fifth clock pulse, a 4-bit Johnson sequence is Q0 = 0, Q1 = 1, Q2 = 1, and Q3 = 1. On the sixth clock pulse, the sequence is ________.
  • A Q0 = 1, Q1 = 0, Q2 = 0, Q3 = 0
  • B Q0 = 1, Q1 = 1, Q2 = 1, Q3 = 0
  • C Q0 = 0, Q1 = 0, Q2 = 1, Q3 = 1
  • D Q0 = 0, Q1 = 0, Q2 = 0, Q3 = 1
Answer: Option C
Q38
The bit sequence 0010 is serially entered (right-most bit first) into a 4-bit parallel out shift register that is initially clear. What are the Q outputs after two clock pulses?
  • A 0000
  • B 0010
  • C 1000
  • D 1111
Answer: Option C
Q39
What is a shift register that will accept a parallel input, or a bidirectional serial load and internal shift features, called?
  • A tristate
  • B end around
  • C universal
  • D conversion
Answer: Option C
Q40
On the third clock pulse, a 4-bit Johnson sequence is Q0 = 1, Q1 = 1, Q2 = 1, and Q3 = 0. On the fourth clock pulse, the sequence is ________.
  • A Q0 = 1, Q1 = 1, Q2 = 1, Q3 = 1
  • B Q0 = 1, Q1 = 1, Q2 = 0, Q3 = 0
  • C Q0 = 1, Q1 = 0, Q2 = 0, Q3 = 0
  • D Q0 = 0, Q1 = 0, Q2 = 0, Q3 = 0
Answer: Option A
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