Exam 3 review problems

What formula is used to calculate Data Rate in communications?

Data Rate = (number of channels) • (samples/second) • (bits/sample)

What does RAM stand for?

RAM stands for Random Access Memory.

What is the speed of light?

300 million meters/second.

What is the speed of sound in air?

340 meters/second.

What is the meaning of 1 Byte?

1 Byte = 8 bits.

In connected communications, is it true that signals travel well for thousands of kilometers between a pair of wires?

True.

Can connected communications carry many voice messages at the same time?

True.

Is it uncommon these days for connected communications?

False.

What memory type is used for semi-permanent storage?

Flash memory.

Which requires power to keep data, Flash memory or DRAM?

DRAM.

Does magnetic storage use magnetic materials to store bits?

Yes.

Is telegraphy a digital form of communication?

False.

Is the Internet regarded as many networks connected together?

True.

Do devices on the internet have a unique machine identifier?

True.

What is the essence of the Internet?

It is essentially a delivery system between computers.

How often does Moore's Law state that the number of transistors doubles?

Every two years.

Are infrared electromagnetic waves useful in communications because they can switch on and off quickly?

True.

Do Flash drives use Field Effect Transistors (FETs)?

True.

Does Wi-Fi always use the same band?

False.

Are capacitors useful in computer memory?

True.

What helps the Global Positioning System (GPS) work accurately?

Electromagnetic waves travel at a predictable speed and receivers calculate their positions by comparing distances from satellites.

Have the density of transistors in integrated circuits doubled three times in the last six years due to Moore's Law?

True.

Which elements are included in materials used in cell phones?

Dozens of different chemical elements.