This Tuesday Self Test question is from the Element 3 General Radiotelephone Operator Class question pool:
What is the voltage range considered to be valid logic low input in a TTL device operating at 5 volts?
A. 2.0 to 5.5 volts.
B. -2.0 to -5.5 volts.
C. Zero to 0.8 volts.
D. 5.2 to 34.8 volts.