Exin CDCP Exam - Topic 2 Question 21 Discussion

Actual exam question for Exin's CDCP exam

Question #: 21
Topic #: 2

[All CDCP Questions]

When dealing with glass door racks, cool air is injected into the rack from:

AThe rear door in a downflow direction.

BThe front door in a downflow direction.

CThe top of the rack through the fans and vents mounted inside the rack.

DThe bottom of the rack.

Show Suggested Answer

Suggested Answer: B

Single-mode cabling and multi-mode cabling are two types of fiber optic cables that differ in their core diameter, wavelength, light source, bandwidth, distance, and cost. Single-mode cabling has a smaller core diameter and uses a laser as a light source, which enables it to transmit data over longer distances and higher bandwidths. However, single-mode cabling is also more expensive than multi-mode cabling, because it requires more precise alignment and splicing, and more costly light sources and connectors. Multi-mode cabling has a larger core diameter and uses LEDs or VCSELs as a light source, which makes it cheaper and easier to install and maintain. However, multi-mode cabling also has a shorter distance and lower bandwidth than single-mode cabling, because it suffers from more modal dispersion and attenuation.

1: Data Center Cabling: Single Mode vs Multimode Fibers2, page 1, section 1 3: Single Mode vs Multimode Fiber Cable Guide4, page 1, section 1 5: Single-Mode vs. Multi-Mode Fiber Cables: Explained6, page 1, section 1 7: 2 Types of Fiber Optic Cable: Single Mode vs. Multimode Fiber8, page 1, section 1

by Huey at Sep 09, 2024, 06:20 PM

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Alline

3 months ago

Yeah, it's all about that rear door airflow!

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Xochitl

3 months ago

Wait, are we sure about this? Sounds off to me.

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Lemuel

3 months ago

Pretty sure it's the top with fans and vents.

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Lynelle

4 months ago

I thought it was from the front door, but I guess not.

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Farrah

4 months ago

It's definitely from the rear door, downflow style!

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Carylon

4 months ago

I feel like it might be the rear door, but I need to double-check my notes on cooling airflow.

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Chaya

4 months ago

I practiced a similar question where air was injected from the bottom, but that doesn't seem right for glass door racks.

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Jesus

4 months ago

I remember something about airflow direction, but I can't recall if it's the front or rear door. This is tricky!

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Tambra

5 months ago

I think the cool air is injected from the top of the rack, but I'm not entirely sure. It seems like a common setup in cooling systems.

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Alverta

5 months ago

This seems straightforward. The question states that the cool air is injected into the rack from the rear door in a downflow direction, so I'll go with that.

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Ilda

5 months ago

Based on my understanding, the cool air is injected from the top of the rack through the fans and vents mounted inside. I'll mark that as my answer.

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Val

5 months ago

I'm a bit confused on this one. I'll need to review the material on glass door racks again before I can answer confidently.

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Gilberto

5 months ago

Okay, let's see. I'm pretty sure the cool air is injected from the rear door in a downflow direction, but I'll double-check my notes to be sure.

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Devon

5 months ago

Hmm, this looks like a tricky one. I'll need to think it through carefully.

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Lezlie

5 months ago

Security scoping sounds like the most relevant option here. It's likely the feature that allows admins to limit user access based on their role. I'll go with that unless I can find a better match.

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Estrella

9 months ago

Wait, are we talking about glass door racks or just regular racks? Because if it's a glass door rack, I'm pretty sure the answer is 'whichever way the janitor is feeling that day.'

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Matthew

10 months ago

Ha! Trick question. The correct answer is actually 'All of the above.' Depending on the rack design, cool air can be injected from any of those locations.

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Rory

8 months ago

Wow, I had no idea it could come from all those locations!

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Wilson

8 months ago

I agree, I thought it was only from the top of the rack.

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Fabiola

8 months ago

Really? I always thought it was just from the rear door.

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Hyun

10 months ago

Option B seems logical to me. Blowing the cool air from the front door in a downflow direction would provide direct cooling to the components.

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Ira

8 months ago

It seems like a consensus, option B it is.

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Glory

9 months ago

I would go with option B as well.

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Rosalind

9 months ago

I agree, blowing cool air from the front door makes sense.

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Peter

10 months ago

I think option B is the best choice.

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Luisa

11 months ago

Hmm, that makes sense too. I guess it could be C.

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Ettie

11 months ago

I disagree, I believe it's C) The top of the rack through the fans and vents mounted inside the rack.

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Luisa

11 months ago

I think the answer is A) The rear door in a downflow direction.

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Brynn

11 months ago

I thought the answer was D. Wouldn't it make more sense to inject the cool air from the bottom of the rack? That's how I've seen it done in most data centers.

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Barrie

9 months ago

I guess it depends on the setup, but injecting from the top seems more efficient.

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Asha

9 months ago

D) The bottom of the rack.

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Roselle

9 months ago

That actually makes sense, injecting cool air from the top.

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Chaya

9 months ago

C) The top of the rack through the fans and vents mounted inside the rack.

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Beckie

9 months ago

Really? I've always seen it come from the front door.

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Martha

9 months ago

B) The front door in a downflow direction.

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Marvel

9 months ago

I always thought it was from the rear door too.

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Justine

10 months ago

A) The rear door in a downflow direction.

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Ivory

10 months ago

User 2: I agree, I think it's from the top to ensure proper airflow.

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Casandra

10 months ago

User 1: I always thought the cool air was injected from the top of the rack.

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Octavio

11 months ago

The correct answer is C. The cool air is injected into the rack from the top through the fans and vents mounted inside the rack. This ensures even cooling throughout the equipment.

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