itsjereguides
WGU D413 –
TELECOMMUNICATIONS &
WIRELESS COMMUNICATIONS
## OBJECTIVE ASSESSMENT (OA)
PRACTICE QUESTION BANK
### 2026-2027 ACADEMIC YEAR |
200+ QUESTIONS WITH DETAILED
RATIONALES
,2|Page
# SECTION 1: TELECOMMUNICATIONS FUNDAMENTALS
## Questions 1-30
### HISTORY & EVOLUTION OF TELECOMMUNICATIONS
#### (Questions 1-5)
### Question 1
**Cognitive Level:** Remembering
What is considered the first practical electrical telecommunications system that enabled long-
distance voice transmission?
A) The telegraph
B) The telephone
C) The radio
D) The internet
---
**Correct Answer: B) The telephone**
**Rationale for Correct Answer:** The telephone, invented by Alexander Graham Bell in 1876,
was the first practical electrical telecommunications system that enabled voice transmission over
long distances. Unlike the telegraph, which transmitted coded messages, the telephone
transmitted the human voice directly, revolutionizing communication.
**Rationale for Incorrect Answers:**
,3|Page
- **A) The telegraph:** The telegraph (1830s-1840s) was an earlier technology that transmitted
coded messages using Morse code, not voice.
- **C) The radio:** Radio (late 19th century) enabled wireless voice transmission but came after
the telephone.
- **D) The internet:** The internet (1960s onward) is a modern network that enables data
communication but is not the first practical voice transmission system.
---
### Question 2
**Cognitive Level:** Understanding
The concept of "bandwidth" in telecommunications refers to:
A) The physical width of a transmission cable
B) The range of frequencies available for data transmission
C) The amount of data that can be stored on a device
D) The number of users connected to a network
---
**Correct Answer: B) The range of frequencies available for data transmission**
**Rationale for Correct Answer:** Bandwidth in telecommunications is the range of frequencies
(measured in hertz) that can be used for transmitting data. A wider bandwidth allows more data
to be transmitted in a given time, directly affecting data rates and network capacity.
**Rationale for Incorrect Answers:**
, 4|Page
- **A) The physical width of a transmission cable:** This is a common misconception;
bandwidth is a frequency measure, not a physical dimension.
- **C) The amount of data that can be stored:** This describes storage capacity, not bandwidth.
- **D) The number of users connected:** This describes network capacity or user count, not
bandwidth.
---
### Question 3
**Cognitive Level:** Applying
A telecommunications technician is measuring the performance of a communication channel.
Which metric describes the ratio of signal power to noise power?
A) Bandwidth
B) Signal-to-Noise Ratio (SNR)
C) Latency
D) Throughput
---
**Correct Answer: B) Signal-to-Noise Ratio (SNR)**
**Rationale for Correct Answer:** The signal-to-noise ratio (SNR) is the ratio of the power of
the transmitted signal to the power of background noise. Higher SNR indicates better signal
quality and more reliable communication.
**Rationale for Incorrect Answers:**