How about another round of QA with your Managing Editor and a few inquisitive customers? Our first item comes from the A+ Essentials (220-701) Practice Exam. The question is:
Your boss wants you to procure an external hard drive for his PC so that it can be quickly backed up. If he wants the quickest backup, which of the following busses should you use? Select the best answer.
A.) IEEE 1394
B.) IEEE 1284
C.) RS-232
D.) USB 2.0
The correct answer is A. Let’s run through why A is the right choice.
Answer choice B, IEEE 1284, is the spec for parallel ports which, when compared to either USB or FireWire (IEEE 1394), is much slower—about 1.5 MB/s. Definitely out. C, RS-232 is the spec for serial ports. Also too slow at 115 KB/s. That leaves A and D. USB 2.0 is an excellent transfer mechanism; but, when compared to FireWire, it’s slower: 480 Mpbs.
Tom from Mariposa CA had a question about the explanation for why FireWire is correct. We explain that FireWire is good for up to 800 Mbps and is, thus, faster than USB 2.0. Tom writes: “IEEE 1394 is 400 Mbps; USB 2.0 is 480 Mbps; IEEE 1394b which is not a choice here, runs at 800.”
Technically, Tom is correct. The b revision for IEEE 1394 is the one that runs at 800 Mbps. But, the community doesn’t refer to FireWire by its revision designation in more common parlance. All things being equal, the IEEE 1394 revision that runs at 400 Mbps is actually IEEE 1394-1995. But we don’t call it that; likewise, we don’t refer to the 2006 revision of the standard as IEEE 1394c-2006. Nor will we call the as yet unreleased (and blazingly fast at 6.2 Gbps!) IEEE 1394 revision as IEEE P1394d. Whatever the currently used FireWire standard is, it will be referred to as IEEE 1394 (or FireWire).
The next item we’ll go over comes from PrepLogic’s CCNA Voice Practice Exam. The question states:
“Using the given analog sound wave diagram, which part of the sound wave depicts the amplitude?” For reference, we’ve included this diagram.
The answer choices are as follows:
A.) Letter A
B.) Letter B
C.) Letter C
D.) Letter D
The correct answer is B.
James from Melbourne, Australia remarks that he “[does not] agree with… letter B. Self study says it’s… Letter C”.
Here’s the rub: the diagram actually shows two different types of amplitude identified by both Letter B and Letter C. So how do you distinguish? Well, only one type of amplitude is important to telecommunications and, thus, the CCNA Voice exam: peak amplitude. Peak amplitude is exemplified by Letter B. Peak-to-peak amplitude (Letter C) is a common way of measuring amplitude, but peak amplitude—the absolute value of the signal, is more appropriate for this measurement.
The last item we want to discuss comes from PrepLogic’s Security+ (SY0-201) Practice Exam. The question:
Which of the following is NOT true about password security?
A.) Passwords are kept secret at all times.
B.) Passwords are of a minimum sufficient length.
C.) Passwords are of a minimum sufficient strength.
D.) Passwords are generated of personal possessions or preferences.
The correct answer is D.
Stuart from Sierra Vista, AZ writes that he sees two answer choices that are repeated. This is actually another excellent demonstration of how CompTIA creates distracters that pull you away from the correct answer. The problem is that, in reading quickly, answer choices B and C do, indeed, look the same. However, if you look closely you’ll see that answer B indicates passwords “of a minimum sufficient length” while answer C indicates passwords “of a minimum sufficient strength.” This just shows that you have to make sure to read your questions very carefully when taking the test.
Ok, that’s all for now. Check back soon for another installment!