# CCNA 1 Module 4 Exam Solutions

Cisco’s exams can be a lot of hard work- we know. But the worst thing you can do to yourself is to simply look up the answers to exam questions. Not only do you not learn anything- but you’re hurting your future in the process.
Instead, shouldn’t you get a helpful hint and get pointed in the right direction of where to look for an answer? That way, you can keep your dignity, hopes for the future, and of course your grade. The questions below are from the CCNA 1 module 4 exam- but instead of straight answers, we reason out why the answers are correct. If any type of math or decision making is involved, we leave that up to you (But we will of course give you the resources you need to complete the question.)

#### 1. To ensure reliable LAN communications, what should a technician be looking for when attaching connectors to the ends of UTP cable?

A) that the white-orange/orange pair is attached first
B) That the wire pairs remain twisted as much as possible
C) that one end of the shield is properly ground but not the other
D) that 50 ohm termination resistors are on both ends

Explanation: Since we know that crosstalk is commonly caused from not keeping wires twisted correctly, we whould look for that first- B is correct. UTP cable isn’t grounded, so C is incorrect. Resistors are used on UTP cable, so D is also incorrect. A is incorrect since it would be rather pointless, unless the wire pairs appear to be twisted and the problem can not be found.

#### 2. Which of the following describes frequency?

A) length of each wave
B) height of each wave
C) number of cycles each second
D) amount of time between each wave

Explanation: Frequency is defined in the article above as “cycles per second,” so C is correct.

#### 3. How are binary ones and zeros represented in fiber optic installations? (Choose two.)

A) +5 volts/-5 volts
B) 0 volts/5 volts
C) light/no light
D) high to low electrical transition
E) low to high electrical transition
F) increasing/decreasing light intensity

Explanation: Fiber optic cable uses light to initiate communication- therefore, we can say that C and F are both correct. Voltage is associated with electricity, not light- and therefore the rest of the answers are incorrect.

#### 4. What is expected when crosstalk is present in networks with higher transmission frequencies? (Choose two.)

A) jitter
B) increase in crosstalk
C) higher signal attenuation
D) increases in cancellation effect
E) destruction of more of the data signal

Explanation: As a higher frequency is obtained, more destruction of the data signal is present, and crosstalk increases. B and D are correct.

#### 5. A small company is experiencing difficulties on its LAN. After performing some tests, a technician has determined that the copper media supporting the LAN is experiencing abnormal attenuation. What are two possible causes of the problem? (Choose two.)

A) defective connectors
B) excessively long cable lengths
C) use of higher grade cabling
D) low frequency signals used in the media
E) network cable runs isolated from other cables

Explanation: Since many problems will be with connectors or long cable lengths, that is what we should check first. The signal degrades over time, so excessive distances will weaken the signal. Connectors that don’t function properly will also, of course, distort or attenuate our signal.

#### 6. What factors need to be considered to limit the amount of signal attenuation in Ethernet cable runs? (Choose two.)

A) type of users
B) number of users
C) length of cable
D) type of electrical equipment
E) installation of connectors on the cable

Explanation: This question directly corresponds to the one above- and therefore, we know that C and E are both correct.

#### 7. What conditions are described when transmission signals from one wire pair affects another wire pair? (Choose two.)

A) noise
B) resistance mismatch
C) jitter
D) crosstalk
E) attenuation

Explanation: We know from the above article that crosstalk and noise both result from signals jumping from one wire to another. Resistance mismatch, jitter, and attenuation are unrelated.

#### 8. What is a cause of crosstalk in UTP cable?

A) cable pairs that are shorted
B) cable pairs crossed during termination
C) cabling runs installed in separate conduit
D) cable pairs that are untwisted because of poor termination of the cable

Explanation: It should be apparent by now that the number one cause of crosstalk is faulty connectors or untwisted wires- therefore, D is correct.

#### 9. Which of the following are detected by the wire map test? (Choose three.)

A) near-end crosstalk (NEXT)
B) opens
C) propagation delay
D) return loss
E) reversed-pair faults
F) short circuits

Explanation: Opens, reversed-pair faults, and short circuits are all detected by a wire map test. We need to use special features of a testing device to test for NEXT, propagation delay, and return loss. It’s possible to test for these things, but not with a wire map.

#### 10. A company needs to extend the LAN to six separate buildings. To limit the amount of signal attenuation on the LAN media, what type of media would be the best to use between the buildings?

A) air (wireless)
B) coaxial cable
C) fiber
D) shielded twisted pair
E) unshielded twisted pair
Explanation: Since fiber can be run for longer distances, and isn’t effected by outside interference, the company should use fiber; C is correct. Wireless would be a poor choice since walls would interfere with the signal. STP and UTP would both be vulnerable to interference, and would also have a much shorter distance capability.