Exam practice
Every question from the end of every unit, with hints and answers to open. After you check an answer, mark how you did, and come back to the ones you didn’t get.
10 questions
Unit 1 · What Is a Computer?
Define a computer. Name its four jobs, and explain each with an example from a mobile phone.
Answer
A computer is a machine that takes in data, processes it by following a program (a set of instructions), gives out the results, and can store data for later.
- Input: data going in. Example: tapping the touchscreen, speaking into the microphone, the camera taking in light.
- Processing: working on the data by following the program. Example: the phone adding numbers in the calculator, or turning the camera’s light into a photo.
- Output: results coming out. Example: the picture on the screen, the ringtone from the speaker, the phone vibrating.
- Storage: keeping programs and data for later, even when switched off. Example: photos, contacts and apps saved in the phone.
Sort these into input devices, output devices and storage: keyboard, printer, memory card, microphone, screen, camera, speaker, pen drive, mouse.
Answer
- Input devices: keyboard, microphone, camera, mouse.
- Output devices: printer, screen, speaker.
- Storage: memory card, pen drive.
What is the difference between hardware and software? Give three examples of each.
Answer
Hardware is the parts of a computer you can touch. Examples: the screen, the keyboard, the processor (also: the battery, the mouse, the printer).
Software is the programs: the instructions that tell the hardware what to do. Examples: a calculator app, a game, the operating system (also: a web browser, a camera app).
A computer needs both: hardware can do nothing without software, and software needs hardware to run on.
Copy and complete the table for an ATM.
| Job | Parts of the ATM that do it |
|---|---|
| Input | |
| Processing | |
| Output | |
| Storage |
Answer
| Job | Parts of the ATM that do it |
|---|---|
| Input | the card slot (reads the card), the keypad and touchscreen (the PIN and amount) |
| Processing | the ATM’s processor, with the bank’s computers checking the PIN and the balance |
| Output | the screen, the cash slot, the receipt printer, the speaker’s beeps |
| Storage | the ATM’s program and a record of every withdrawal, in the ATM and in the bank’s computers |
A plain rice cooker and a rice cooker with buttons and a display both cook rice. Which of them has a computer inside? How can you tell?
Answer
The one with buttons and a display has a computer inside. It follows a program: it takes in your choice from the buttons and the pot’s temperature from a sensor (input), decides when to heat hard, heat gently or keep warm by following its program (processing), switches the heater and the display (output), and stores its menus and the time you set (storage).
The plain one has only a thermostat switch, which clicks to “warm” when the pot gets hotter than boiling water. Its one rule is built into the switch; it follows no program and can’t store anything.
Name five machines in your home or town that have a computer inside, and give the input and output of each.
Answer
Any five, for example:
- a mobile phone: input touchscreen, microphone, camera; output screen, speaker.
- a digital rice cooker: input buttons, temperature sensor; output heater, display.
- a traffic light controller: input crossing button, sensors for cars; output the lamps.
- an ATM: input card slot, keypad; output screen, cash, receipt.
- a washing machine: input dial, buttons, water-level sensor; output motor, pump, heater, display.
- a television: input the remote’s signals; output the picture and sound.
Describe how computers are used in three kinds of work in Nepal, and say what problem each solves.
Answer
Any three, for example:
- A bank: ATMs and the bank’s computers keep every account and let people take out money at any hour. They save queues and keep a record of every rupee that can’t be lost.
- A hospital: X-ray and ultrasound machines turn signals from inside the body into pictures, and computers keep each patient’s records. Doctors can see inside the body without cutting, and see what was done before.
- A farm: a farmer’s phone brings the weather forecast and the market prices. The farmer knows when to plant or harvest and can sell at a fair price.
- A shop: a barcode scanner and billing computer add up bills quickly and correctly and count what is left to sell.
Put these in the order they happened, and write one sentence about who made each: ENIAC; the bead abacus; the microprocessor; Pascal’s calculating machine; Ada Lovelace’s program; the World Wide Web.
Answer
- The bead abacus (hundreds of years ago, after thousands of years of counting boards): people in China, and later Japan, used beads on rods to help with sums; no single inventor is known.
- Pascal’s calculating machine (1642): Blaise Pascal built it in France to help his father, a tax official.
- Ada Lovelace’s program (1843): Ada Lovelace wrote it in England for Charles Babbage’s Analytical Engine.
- ENIAC (1945): built at the University of Pennsylvania, paid for by the United States Army, and programmed by six women.
- The microprocessor (1971): made by Intel’s engineers with Masatoshi Shima of Busicom, a Japanese calculator company.
- The World Wide Web (1989): invented by Tim Berners-Lee at CERN in Switzerland.
Give one example each of an individual, an organization, a government and a community shaping computing. What could each do that the others could not?
Answer
- An individual: Ada Lovelace wrote the first published program. One person can have a new idea and work it out in detail.
- An organization: Intel made the first microprocessor with Busicom. A company can pay a large team and make millions of chips.
- A government: Nepal’s government brought in a computer for the 1971 census (or: the US Army paid for ENIAC). A government can pay for huge projects and serve the whole country.
- A community: volunteers write the Nepali Wikipedia (or: people around the world write free software together). A community can share knowledge freely with everyone, without being paid.
The same phone can be a calculator, a torch, a map and a camera. Explain how, using the words hardware and software.
Answer
The phone’s hardware (its screen, processor, storage, camera, light and so on) stays the same. What changes is the software: each app is a different program, a different set of instructions telling the same hardware what to do. Open the calculator app, and the processor follows instructions for sums; open the torch app, and it follows instructions to switch on the light. This is what makes a computer special: it can do any job that someone writes a program for.