1. When was the telephone invented and by whom?
2. State the velocity of sound in air. Is it higher in air than in a denser medium?
3. State and define the characteristics of sound.
4. Make sketch of Bell's original magneto telephone without permanent magnets.
5. Describe and sketch Hughes' microphone.
6. Which is, at present, the best material for varying the resistance in transmitters?
7. Give the fundamental differences between the magneto transmitter and the carbon transmitter.
8. What is the function of the induction coil in the telephone circuit?
9. Describe and sketch the different kinds of visible signals.
10. What should be the diameter of hard drawn copper wire in order to allow economical spacing of poles?