Physical Layer Summary Questions¶

The questions are randomised per student, and for these questions you will only receive correct/incorrect feedback. In Problem 1, each question has exactly one correct answer.

In Problem 2, each student will have at least one correct option, usually more. For a partially correct answer, Plussa gives feedback incorrect, but Problem 2 is accepted when the score is 12 or more, and the points are shown with a yellow background. Points only start to accumulate when more than half of the selections in the task are correct. The score alone does not directly indicate whether an individual selection is correct.

Question 1

What is the normal data transfer distance for the short-range communication technology NFC?

Over 1 kilometer.

About 500 meters.

A few centimeters.

Exactly 15 meters.

Question 2

Regarding NFC as a short-range communication technology:

NFC works only at such short distances that it cannot be attacked.

Even though NFC operates only at short distances, an attacker can still intercept traffic.

In NFC technology, security relies on the short range of the transmission signal.

NFC is the most secure wireless communication technology.

Question 3

Which of the following situations is NFC technology intended for?

Backing up a laptop.

Sharing an Internet connection from a laptop to a mobile device.

A payment transaction using a mobile device.

Watching movies from an online service.

Question 4

How is the physical transmission path of an NFC connection implemented?

With fiber-optic technology

With coaxial cabling

With LED technology

With radio wave technology

Question 5

Which of the following terms is closely related to NFC connections?

LTE

WLAN SSID

RFID

VLAN

Question 6

For what purpose are NFC implementations intended?

Only for military purposes.

Freely for general use.

For special needs of emergency services.

Restricted, requires an applied radio license.

Question 7

Which of the following disturbances may affect the physical transmission path?

Hard disk failure

Router failure

Electromagnetic interference

Corruption of a mobile phone’s memory card

Question 8

In wireless communication, the physical layer

is responsible for signaling on the transmission path.

ensures files are transferred intact.

handles routing the connection to the correct destination.

is responsible for encrypting the data transfer.

Question 9

Devices communicating with NFC can infer their location by using GNSS/GPS or the cell-IDs of their base stations. In such a context,

both methods typically prove the proximity of the devices with same accuracy.

the cell‑ID method depends on accurate, trustworthy base‑station location data.

enforcing time constraints for NFC messages would not help in verifying proximity of the devices.

NFC protocol alone guarantees that the two devices are a few centimeters apart, so location sensing for proximity verification is unnecessary.

Question 10

This module treated one of the aspects of the CIA triad very little. The same is true of the entire material - in proportion to the treatment of the other two. Which aspect is it, and what is the reason in this module?

C: cryptology has its own specialiced courses, and physical layer would not do encryption anyway.

C: this course goes without strong mathematical prerequisites that hardware encryption would need.

I: as long as it can decode a signal the physical layer need not be concerned of its integrity.

I: integrity is not important before authentication is done on a higher layer.

A: nothing can be done to prevent jamming of signals.

A: protections against jamming and destructing of signals is the field of study of specialized courses.

Select the correct statements. You can choose one or more options.

Question 1

Physical layer tasks and security—Which are correct?

The physical layer’s task is to handle signaling for the chosen transmission path (wireless/cable).

The physical layer’s task is to identify the user when they want to transfer data.

Physical layer security includes controlling/preventing/limiting the spread of the transmission signal beyond the transmission path.

Physical layer security means preventing/restricting an attacker’s physical approach to the transmission path.

In wireless communication, the physical layer’s task is to know the state of data transfer according to the TCP protocol.

In wireless communication, the physical layer must, in addition to data transfer, maintain the connection through signaling.

It is not possible to implement security measures at the physical layer.

The physical layer prevents an attacker from seeing the data transfer between communication parties.

Using the physical layer in data transfer enhances and ensures confidentiality.

In wireless communication, the physical layer handles modulation, synchronization, and transmission path control.

In wireless communication, physical layer techniques can identify a device based on fingerprinting.