ISS 2016 Statistics Paper-1 Solution: Question 77 (Scanner, Processor, Monitor and Printer Basics)
Continuing our question-by-question walk through the ISS Statistics Paper-1 previous year papers, we now arrive at a question from the 2016 paper that trips up a surprising number of candidates — not because the statistics is hard, but because it isn't statistics at all. It's a general computer awareness question, and those get skipped in revision far more often than they should.
Quick Summary
Topic: Computer Awareness – Hardware and Peripherals (scanners, processors, monitors, printers)
Question Reference: ISS 2016, Statistics Paper-1, Question 77
Correct Answer: Option (c) — Statements 1, 2 and 4 only
The Question, As Asked
77. Which of the following statements are correct?
Scanner resolution is measured in dpi.
Processor speed is measured in GHz.
An LCD monitor uses less power than an LED monitor.
Laser printers use the same technology as photocopiers.
Select the correct answer using the code given below:
(a) 1, 2 and 3 only
(b) 1, 3 and 4 only
(c) 1, 2 and 4 only
(d) 2, 3 and 4 only
Step 1: Check Statement 1 – Scanner Resolution
A scanner builds a digital image of a physical page by sampling it as a fine grid of tiny dots. The resolution of that grid — how many of those dots are packed into one inch of the original page — is the measure that tells you how sharp or detailed the scanned image will be. This unit is called dpi, short for "dots per inch". A scan done at 300 dpi captures 300 dots across every inch of the page; a scan at 600 dpi captures twice as many dots in the same space, which is why it looks sharper when you zoom in. So Statement 1, "scanner resolution is measured in dpi", is a plain, correct statement of fact.
Step 2: Check Statement 2 – Processor Speed
A computer's processor (the CPU) does its work in discrete "ticks" paced by an internal clock. Each tick lets the processor carry out a basic step of an instruction, and the number of ticks it can complete in one second is called its clock speed. This is measured in Hertz (Hz), the standard unit for "cycles per second" in physics. Since a modern processor completes billions of these cycles every second, its speed is normally quoted in gigahertz (GHz), where one GHz equals one billion cycles per second. A processor advertised as "3.2 GHz" is completing 3.2 billion clock cycles every second. So Statement 2 is also correct.
Step 3: Check Statement 3 – LCD vs LED Power Consumption
This is the statement that decides the whole question, so let's slow down here. An "LED monitor" is not a separate display technology from an LCD monitor — it is still an LCD panel underneath. The only difference is how the screen is lit from behind:
Older/standard LCD monitors use CCFL (cold cathode fluorescent lamp) tubes as the backlight.
LED monitors use an array of light-emitting diodes as the backlight instead.
LED backlighting is more power-efficient than CCFL backlighting — LEDs convert more of the electricity they draw into usable light, run cooler, and can be dimmed selectively across the screen rather than lighting the whole panel uniformly. The practical result is that an LED-backlit monitor consumes less power than a standard CCFL-backlit LCD monitor, not the other way around. Statement 3 says "an LCD monitor uses less power than an LED monitor" — which reverses the actual relationship. So Statement 3 is false.
Pro Tip: Computer awareness questions love to flip a true relationship on its head and hand it back to you as a trap option. The safest habit, the one that's usually drilled into students until it becomes automatic, is to never just recognise the technical terms in a statement — restate the comparison in your own words first ("which one is cheaper to run, LCD or LED?"), answer that plain-language question from what you actually know, and only then match it back to the statement as written. That one extra second of translation is often the difference between falling for the reversal and catching it.
Step 4: Check Statement 4 – Laser Printers and Photocopiers
A laser printer works by using a laser beam to charge a rotating drum in the exact pattern of the page to be printed. Fine toner powder sticks only to the charged areas of the drum, and the drum then presses that toner onto paper, which is fused permanently using heat. This process is called xerography (electrophotographic printing). A traditional photocopier uses this exact same drum-and-toner process — the only real difference is where the "image" being copied comes from: a photocopier scans a physical original in front of it, while a laser printer receives the page as digital data from a computer. The underlying print mechanism, the laser-charged drum and toner, is identical. So Statement 4 is correct.
Step 5: Combine the Results and Match the Code
Putting it together:
Statement 1 – Correct
Statement 2 – Correct
Statement 3 – Incorrect
Statement 4 – Correct
The statements that are correct are 1, 2 and 4. Scanning the four answer codes, that combination appears only in option (c): "1, 2 and 4 only". This matches the official ISS 2016 answer key, which also records the answer to Question 77 as (c).
Why This Question Matters
It is tempting to treat the "general computer awareness" items in the ISS Paper-1 as free marks that need no preparation, and then lose them anyway to a single reversed statement like the LCD/LED one above. Questions like this exist precisely to separate candidates who vaguely recognise terminology from those who understand how the underlying hardware actually behaves. A handful of these questions, revised properly in the weeks before the exam, is one of the cheapest sources of marks on the whole paper — cheaper, certainly, than squeezing out one more statistics derivation under time pressure.
Frequently Asked Questions
Is "LED monitor" really just an LCD monitor with a different backlight?
Yes. Both LED and standard LCD monitors use liquid crystal display panels to form the image. The "LED" label refers only to the backlighting technology used to illuminate that panel from behind, not to a different kind of screen.
Why does LED backlighting save power compared to CCFL?
LEDs convert electrical energy into light more efficiently than CCFL tubes, generate less waste heat, and can be switched off or dimmed in dark regions of the screen (in panels with local dimming), all of which reduce overall power draw.
Is dpi the same thing as pixel resolution (like 1920x1080)?
No. Pixel resolution describes the total count of picture elements in a digital image, while dpi describes density — how many of those dots are packed into one physical inch when scanning or printing. The same pixel count can correspond to different dpi values depending on the physical size of the scanned area.
Why is processor speed measured in GHz instead of plain Hz or MHz?
Modern processors complete billions of clock cycles per second, and GHz (gigahertz, one billion cycles per second) keeps the numbers in a convenient, human-readable range rather than writing out nine-digit Hz figures.
Do laser printers and photocopiers share any other similarities besides the drum mechanism?
Both typically use toner cartridges, a fuser unit that uses heat and pressure to bond toner to paper, and a photosensitive drum. The core difference remains the image source: a scanned original for a copier versus a digital file for a printer.
Should I expect more computer awareness questions like this in ISS Paper-1?
Yes, Paper-1 consistently includes a block of general computer and IT awareness questions alongside the core statistics syllabus, which is exactly why this series works through them in sequence rather than skipping past them.
If anything in this breakdown felt unclear, or if you spotted a nuance worth discussing further, drop a comment below — and if you know a fellow aspirant who's working through the same ISS Paper-1 papers, consider sharing this post with them.
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