Punjab PSEB Matric Computer Science common mistakes
Punjab PSEB Matric Computer Science · Understand the traps and how to avoid them.
Writes that RAM is permanent/non-volatile storage and ROM is temporary, or calls the hard disk the computer's main memory.
Everyday language uses 'memory' for storage (phone '64 GB memory'), and RAM and ROM are both taught as 'memory', so candidates memorise the names without the volatility distinction.
What to do instead
Compare RAM and ROM on three axes in a written table: volatility, read/write ability, and contents. RAM is read/write, volatile, holds the OS and running programs, and loses data on power-off; ROM is read-only, non-volatile, and holds firmware such as BIOS/POST instructions. Classify primary memory as RAM, ROM and cache, and secondary storage as HDD, SSD, DVD and pen drive. Anchor with the desk/cupboard analogy: RAM is the desk you work on, secondary storage the cupboard, ROM the printed instruction plate fixed to the machine.
Converts storage units decimally (1 KB = 1000 bytes, 1 MB = 1000 KB) or writes Mb and MB interchangeably, so answers are off by a factor of 8 or 1024.
Decimal thinking from maths and everyday rounding, plus internet plans advertised in Mbps while file sizes appear in MB, and the notation b/B is visually easy to miss.
What to do instead
Memorise the ladder and multiply by 1024 each step: byte → KB → MB → GB → TB. Write the rule in capitals: uppercase B = byte = 8 bits; lowercase b = bit. Practise one conversion chain aloud: 2 GB = 2 × 1024 MB = 2048 MB. For network speed, divide Mbps by 8 to get MB/s, and show the unit cancellation in the working. In MCQ options, first check whether the unit is b or B before calculating.
Deletes a desktop shortcut to free disk space and reports that the program and its files have been removed, or believes the program is uninstalled.
A shortcut icon looks almost identical to the program icon, and Windows deletes it without any warning; the small arrow overlay is easy to overlook.
What to do instead
Explain that a shortcut is a small .lnk file that only stores the target path. Deleting it removes the link, not the application. To uninstall, use Settings > Apps > Installed apps (or Control Panel > Programs and Features). To inspect the real location, right-click the shortcut > Properties > Target. If a shortcut was deleted by accident, restore it from the Recycle Bin. To confirm what is actually installed, check the program's folder in Program Files.
Presses Enter repeatedly to push content onto a new page; after editing earlier text, headings jump to the wrong page and the layout collapses.
Enter is the fastest visible action and empty paragraph marks are invisible by default, so the document appears to work until content is added or removed.
What to do instead
Teach the manual page break: Ctrl+Enter, or Insert > Page Break, or Layout > Breaks > Next Page. Turn on Show/Hide ¶ (Home tab) so paragraph marks and page breaks become visible and can be deleted individually. Remove runs of empty paragraphs with Find & Replace, searching ^p^p. For headings that must stay with following text, use Keep with next in Paragraph settings rather than adding blank lines.
Aligns columns and centres titles by pressing the spacebar many times, so columns go crooked as soon as the font, size or margins change.
Spaces look aligned in the default font, no guides are visible, and the spacebar gives instant visual feedback, so the habit feels correct.
What to do instead
Explain that in proportional fonts a space, an 'i' and a 'W' have different widths, so spacing never stays aligned. Use Tab stops from the ruler (left, centre, right, decimal) or insert a table for column layouts. Centre headings with paragraph alignment (Ctrl+E), not spaces. Turn on Show/Hide ¶ to reveal dots for spaces and arrows for tabs, then replace them. Demonstrate how the layout survives a font change when tabs and alignment are used.
Selects only one column (for example the marks column), clicks Sort A→Z, and reorders those marks independently of the students' names, corrupting the record.
The selected column highlights and the sort appears to work; the 'Expand the selection' prompt is often dismissed or accepted without reading, and candidates do not connect rows with records.
What to do instead
Teach the rule that one row = one record, so rows must move together. Click a single cell inside a contiguous block and use Data > Sort; or select the whole range including the header row. Tick 'My data has headers' so the header is not sorted as data. Read the 'Expand the selection' prompt and choose that option. Before any sort, save a copy or use Undo (Ctrl+Z) to recover.
Types =A1+B1 and drags the fill handle while expecting a fixed rate cell to stay constant, or types A1+B1 without '=' and wonders why the answer appears as text.
Relative referencing is invisible in the formula, the copied formula looks similar at a glance, and the '=' rule is treated as optional punctuation rather than syntax.
What to do instead
State that every formula begins with '=' and that references are relative by default and shift when copied. Use absolute references with dollar signs, for example =B2*$F$1, and press F4 to cycle A1 → $A$1 → A$1 → $A1. For totals use a function, for example =SUM(B2:B10), not a long chain of plus signs. Verify by clicking the copied cell and reading the formula bar, or press Ctrl+` to display all formulas.
Says an animation was applied so that one slide follows another, or applies a transition to a picture and calls it an animation.
Transitions and animations sit close together on the ribbon and both produce movement, so the terms are used interchangeably in casual speech.
What to do instead
Define the boundary clearly: a transition is the effect between one slide and the next and is set on the slide; an animation is an effect on an object inside a slide (entrance, emphasis, exit, motion path) and is set in the Animation Pane. In Slide Sorter view, transition icons appear under each slide thumbnail. Use the Animation Pane to list object effects and their timing: On Click, With Previous, After Previous. Ask candidates to label a described effect as transition or animation in one-line drills.
Puts every recipient in To or Cc when sending a class notice, exposing all email addresses, or uses Cc when the purpose was to hide recipients.
To is the default and most familiar field, Cc and Bcc look alike, and the mistake produces no error message, so nothing signals the privacy leak.
What to do instead
Assign one job to each field: To = people who must act; Cc = visible copy for information; Bcc = hidden copy. For group notices, put your own address in To and the group in Bcc, or use a proper mailing list. Explain that anyone receiving a Cc can see the other Cc addresses, and that forwarding exposes them further. Treat sharing others' addresses without consent as a privacy and cyber-safety issue, not just etiquette.
Treats the padlock and https as proof that a website is genuine and safe, then enters a password or OTP on a lookalike domain.
Safety advice is often shortened to 'look for the padlock', and encryption is confused with trustworthiness of the site owner; the address bar is rarely read character by character.
What to do instead
Separate the two ideas: the padlock means the connection is encrypted, not that the site is honest. Check the exact domain spelling, the certificate owner, and whether the site was reached by typing the address or through a link. Treat urgency, prize offers, shortened links and requests for OTP, PIN or password as warning signs. Type the address yourself or use a bookmark, and report suspected phishing. Also distinguish phishing (deceptive message), spam (unsolicited bulk mail) and malware (harmful software).