Digital Electronics-Signals and Switches
Digital Electronics-Signals and Switches
11. The serial format for transmitting binary information uses:
- a single conductor
- multiple conductors
- infrared technology
- fiber-optic
12. Which device(s) have almost ideal ON and OFF resistances?
- electromechanical relays
- manual switches
- semiconductor devices (diodes and transistors)
- electromechanical relays and manual switches
13. A diode placed in parallel across a relay coil serves what function?
- to regulate input voltage
- to protect the coil from arcing
- to ensure most of the current passes through the coil
- to reduce arcing across the relay contacts
14. Serial communication can be sped up by:
- using silver or gold conductors instead of copper
- using high-speed clock signals
- adjusting the duty cycle of the binary information
- using silver or gold conductors instead of copper and high-speed clock signals
15. TTL logic chips must have connections to Vcc and ground, even if all inputs and outputs are properly used and tied to valid signals.
- TRUE
- FALSE
16. An indication of cutoff in an NPN bipolar transistor is that the:
- collector current is maximum
- collector-to-emitter voltage equals zero
- base-to-emitter voltage equals 0.7 V
- collector to emitter appears to be open
17. Normal operation of an NPN bipolar transistor requires the base to be ________ with respect to the emitter, and ________ with respect to the collector.
- positive, negative
- positive, positive
- negative, positive
- negative, negative
18. The abbreviation NO, when used with respect to electromechanical relays, stands for not operational.
- TRUE
- FALSE
19. In a graphical representation of voltage versus time, ________ is displayed on the ________ axis and ________ is displayed on the ________ axis.
- time, y, voltage, x
- voltage, y, time, x
20. What is the minimum voltage required before a diode will allow current to flow between the cathode and the anode?
- 0.7 V
- 0.07 V
- 4.3 V
- 0.2 V