PHYS345 Second Midterm Exam, November 24, 1998

1.

  1. What is the amplitude of the pulse observed at the other end of the cable if it has been terminated with a 75 ohm resistor?     6.0 V

  2. Use Karnaugh mapping to find a suitable combination of two-input gates for this truth table.     A.B' + C.A'

  3. Suggest a single three-input gate that can replace this mess.     3-input AND


2.

What should R be for the lamp to flash every 1.5 sec?     11 megaohm


3.

What is the voltage of the signal at the oscilloscope?     4.55 V

What is the ratio of the signal voltage to the noise voltage at the oscilloscope in dB?     14.0 dB (updated, assuming noise source is at Thevenin generator!)

What is the new signal-to-noise ratio?     25.4dB (updated)


4.

Show the type of gate and the connections to the flip-flops needed:     D1 = Q'1 . Q'2


5.

2-bit state diagram


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Last updated May 22, 2005.
Copyright George Watson, Univ. of Delaware, 1998.