Tech+ common mistakes
Tech+ · Understand the traps and how to avoid them.
Answering a question about where a file or application 'lives' by choosing RAM instead of the drive, or describing RAM as the place data is kept after the power is off.
Everyday speech uses 'memory' for both storage and RAM, and phone marketing ('64 GB memory') reinforces the confusion, so the candidate reads the question through that habit instead of the exam's technical definition.
What to do instead
Before answering any hardware question, silently define the two terms: RAM is volatile working space cleared at power-off; a drive/NVMe/SSD is non-volatile storage. Then test each answer choice against 'does this survive a reboot?' - if the stem mentions persistence or capacity of installed programs, the answer must be storage.
Selecting UDP for a file transfer or DNS-style workload when the scenario requires guaranteed delivery, or picking TCP for live video/voice where latency matters more than retransmission.
Candidates memorise 'TCP = reliable, UDP = fast' as slogans and never map the slogan onto the workload described in the stem, so the choice is driven by whichever word feels more positive.
What to do instead
Build a two-column mental table: TCP for file transfer, email, web pages, anything where a lost packet must be resent; UDP for live streaming, VoIP, DNS lookups, gaming where a late packet is worthless. Read the stem for the consequence of loss (corrupted file vs momentary glitch) and choose from that consequence.
Choosing 'IaaS' for a scenario where the provider manages the operating system and runtime and the customer only deploys code, or choosing 'SaaS' for a scenario that requires managing virtual machines.
The three service models are learned as a list of acronyms rather than as a line showing who manages what, so candidates guess based on the word 'cloud' in the stem.
What to do instead
Draw the responsibility line before answering: IaaS = you manage OS upward; PaaS = you manage only your app and data; SaaS = you manage only your account and data. Find the phrase in the stem describing the lowest layer the customer still controls, and match that layer to the model.
Mixing up decimal and binary prefixes - treating 1 GB as 1024 MB in a marketing-capacity question, or treating 1 Gb/s as 1 GB/s when estimating transfer time.
Operating systems report binary values while drive and network vendors use decimal and bits, so candidates carry whichever convention they last saw on their own machine into the exam.
What to do instead
Keep two rules visible: lowercase b = bits, uppercase B = bytes, so divide by 8 when converting a link speed to file size; and read the stem's units before doing arithmetic. If the question is about advertised drive capacity use 1000-based, if it is about what the OS reports use 1024-based, and state which one you used.
Assuming a program that ships as source code is free to use commercially, or labelling a zero-cost proprietary tool as open source.
'Free download' and 'open source' are treated as synonyms in consumer software culture, and the difference between cost, licence terms, and source availability is never separated.
What to do instead
Separate the three axes explicitly: cost (free vs paid), source availability (open vs closed), and licence rights (permissive vs copyleft vs proprietary EULA). For any licensing question, locate the stem's clue about modification or redistribution rights - that is the axis being tested, not price.
Answering a 'how is this code run' question by claiming a language such as Python or JavaScript is compiled to machine code before execution, or that a compiled binary needs the source file at runtime.
Candidates learn languages by popularity rather than by execution model, and the existence of bytecode/JIT tools blurs the textbook compiled/interpreted split.
What to do instead
Classify by the artefact produced: compiled languages emit a standalone machine-code or bytecode file executed directly by the OS or runtime; interpreted languages are read and executed statement by statement by an interpreter at run time. When a language can do both, answer the general case the exam expects and note the exception instead of choosing based on the exception.
Confusing the Scrum Master with the Product Owner - assigning backlog prioritisation and value decisions to the Scrum Master, or assigning process facilitation to the Product Owner.
Both roles are 'non-coding leadership' roles in the same framework, so they collapse into one vague 'manager' bucket in memory.
What to do instead
Anchor each role to one deliverable: Product Owner owns the backlog and decides what and in what order; Scrum Master owns the process and removes impediments; the team owns how. For any agile question, ask 'is this a what/priority decision or a how/process decision?' and route accordingly.
Swapping primary and foreign keys - calling the referencing column in a child table the primary key, or claiming a foreign key must be unique within its own table.
Both are described as 'keys' that link tables, and candidates remember the relationship direction backwards under time pressure.
What to do instead
Use the one-to-many sentence test: the primary key uniquely identifies one row in its own table (one customer); the foreign key repeats in the child table to point back at it (many orders). If the column can legitimately appear on several rows of the same table, it cannot be that table's primary key.
Treating encryption as the answer for every security scenario - picking 'encrypt the data' for a question about verifying who sent a message or proving a file was not altered.
Encryption is the most familiar security control, so it becomes a default answer even when the requirement is authenticity or integrity rather than confidentiality.
What to do instead
Map the requirement word to the control before looking at choices: confidentiality = encryption, integrity = hashing, authenticity/non-repudiation = digital signature, availability = redundancy/backups. Read the stem for 'cannot read', 'was not changed', or 'prove it came from', and choose the matching control.
Reversing public-key direction - saying you sign with the recipient's public key, or that you encrypt a confidential message with your own private key.
The words 'public' and 'private' are learned as a pair without attaching the owning party, so the mapping flips under exam pressure.
What to do instead
Memorise one sentence with the owners named: to send a secret, encrypt with the receiver's public key so only the receiver's private key opens it; to prove origin, sign with the sender's private key so anyone with the sender's public key can verify. Substitute the named people in the stem and check the sentence still makes sense.