1. Which device provides isolation between RS-232 and RS-485: (a) Capacitor (b) Opto-isolator (c) Integrator (d) Resistor
2. What is the maximum range for RS-422: (a) 500 m (b) 1.2 km (c) 5 km (d) 10 km
3. Outline the advantages of balanced lines as opposed to unbalanced lines.
4. What is the bandwidth of a telephone line: (a) Almost infinite (b) 400 Hz to 3.4 kHz (c) 400 Hz to 20 kHz (d) 400 Hz to 100 kHz
5. How does a modem transmit at 9600bps, when the symbol rate is 4800 symbols/sec (baud): (a) It sends two bits for every symbol sent (b) Its impossible as the bit rate is always the same as the symbol rate (c) It hides data (d) It uses more than one data line.