Final Exam Model Paper 8

bool (a Boolean): it has only two values, True and False.

A copy of the string with every capital letter made small: "Ulleri".lower() is "ulleri".

In poor light the camera keeps its shutter open longer to collect enough light, so any shake while it is open blurs the photo. Holding the phone steady stops the shake.

It runs one small program, the same one, all day, every day: checking a few sensors and switching a pump needs very little work. Being small and slow, it costs little and uses very little electricity.

2,000 × 1,500 = 3,000,000 pixels: a quarter of the 12,000,000 it had.

Line 5 is indented under the for, so it runs on every round of the loop. Take away its indent, so that it comes after the loop and runs once, when all 5 days have been added.

Don’t rely on the chatbot: ask a health worker or a pharmacist, or follow the medicine’s own leaflet. A wrong dose could hurt him, and a chatbot can give a wrong answer in confident words that she can’t check.

• i.It prints Poon Hill is at altitude meters. "altitude" in quotes is a string, the word itself, not the variable; Python prints it as it is.
• ii.Leave out the quotes, so that Python uses the variable’s value:

altitude = 2860altitude = altitude + 350print("Poon Hill is at", altitude, "meters")

Poon Hill is at 3210 meters

i. / gives a float, and 2,900 ÷ 3 doesn’t come out exactly; round() with no second number rounds it to a whole number:

Each pays: 966.6666666666666Each pays: 967

ii. 3 × 967 = Rs 2,901, one rupee more than the fare: each share was rounded up, by about 33 paisa, and the three bits add up to about a rupee.

i. The first call gives no rate, so rate takes its default, 1500: 2 × 1,500 = 3,000. The second gives 2500: 2 × 2,500 = 5,000.

30005000

ii. A TypeError: nights has no default, so it must be given. rate is optional; nights isn’t.

def average_speed(km, hours):    return km / hours print("Bina:", average_speed(16, 5))print("Rohit:", average_speed(15, 4))

Bina: 3.2Rohit: 3.75

Rohit walked faster.

• i.Resize a copy (keeping the original) to 800 pixels wide. The width is divided by 5 (4,000 ÷ 800), so the height is too: 3,000 ÷ 5 = 600. It will be 800 × 600 pixels.
• ii.Save it as a JPEG with the quality a little lower (about 80), only as low as needed. A screenshot makes a new picture of the screen, at the screen’s size, with the phone’s bar along the top, and often a bigger file.

• i.Input: a sensor measuring the water level. Output: the pump. The relay is a switch worked by electricity: the board’s small current turns on the big current the pump’s motor needs.
• ii.Leave the pump off (and sound a warning), even if the roof tank is low: a pump that runs with no water burns out.

Any one benefit: apps and services that fit you (a map that knows the traffic); safety (a bank blocks a login from a strange place); free apps, paid for by ads; for everyone, disease outbreaks found early, aid sent where people are, roads and buses planned where people travel; research that needs many people’s data.
Any one risk: it can be used against you (ads when you are weakest, prices set by what you will pay); it can leak in a data breach; scammers use leaked data to sound real; wrong guesses can decide things, such as a loan refused; it lasts for years and may be used for things nobody has thought of yet.

Binita’s is evidence: something that happened, told by the person it happened to. It is weaker evidence, one guide’s story, but it counts if she says what it is. Anil’s is not evidence: a chatbot’s answer is likely words, not a source. Chandan’s is not evidence either: likes measure how many people watched, not whether it is true.

i.

load = 0weight = int(input("Weight of the bag in kg (0 to stop): "))while weight != 0:    if weight < 0:        print("A weight can't be below 0. Try again.")    elif load + weight > 25:        print("Too heavy: find another porter for this bag.")    else:        load = load + weight        print("Load so far:", load, "kg")    weight = int(input("Weight of the bag in kg (0 to stop): "))print("The porter carries", load, "kg.")

For the bags 8, 12, −3, 7 and 5:

Weight of the bag in kg (0 to stop): 8Load so far: 8 kgWeight of the bag in kg (0 to stop): 12Load so far: 20 kgWeight of the bag in kg (0 to stop): -3A weight can't be below 0. Try again.Weight of the bag in kg (0 to stop): 7Too heavy: find another porter for this bag.Weight of the bag in kg (0 to stop): 5Load so far: 25 kgWeight of the bag in kg (0 to stop): 0The porter carries 25 kg.

ii. For example: bags of 20 and 5 should reach exactly 25 kg and be allowed (“Load so far: 25 kg”); bags of 20 and 6 would make 26 kg, so the 6 should be refused (“Too heavy…”). (A first bag of 25, allowed, and of 26, refused, are also edge tests.)

i.

• ii.After each look, binary search throws away half the list: if the name it wants comes after the middle one, it knows the name can only be to the right. That is true only when the list is in order; in a jumbled list, the name could be on either side, and the search could miss it.
• iii.10 looks: each look halves what is left, and 1,000 halved 10 times is less than 1.

• i.Only the title, घोरेपानी, shown on the browser’s tab (and in bookmarks and search results). The head holds information about the page: the charset and the link to the style sheet are used by the browser but not shown.
• ii.A semicolon is missing after darkgreen. The browser reads darkgreen font-size: 40px as one strange color and skips it, without any message, so both declarations are lost. Add the semicolon: color: darkgreen;.

iii.

• The alt text “photo” tells a blind visitor nothing. Say what it shows, in Nepali: alt="पुनहिलबाट देखिएको हिमालमा सूर्योदय".
• There is no viewport line, so a phone lays it out as a screen about 980 px wide and shrinks it. Add <meta name="viewport" content="width=device-width, initial-scale=1"> in the head.

• i.Computers in data centers, run by companies, that he reaches over the internet: his files are on someone else’s disks, far away.
• ii.Syncing big videos uses a lot of data, which would use up his mobile data pack (and cost money).
• iii.Anyone who gets the link, not only the group: a link set to “anyone with the link” means exactly that, and it can be forwarded.
• iv.His account: lose it, and he loses every file in it, on every device. (That is why the account needs strong protection and a way back in.)

too_fast = 0before = int(input("Altitude at the start: "))for night in range(1, 6):    altitude = int(input(f"Altitude on night {night}: "))    climb = altitude - before    print("Higher by", climb, "m")    if altitude > 3000 and climb > 500:        print("Too fast: plan a rest day")        too_fast = too_fast + 1    before = altitudeif too_fast == 0:    print("A safe plan")else:    print("Nights too fast:", too_fast)

Altitude at the start: 2860Altitude on night 1: 2610Higher by -250 mAltitude on night 2: 3440Higher by 830 mToo fast: plan a rest dayAltitude on night 3: 3440Higher by 0 mAltitude on night 4: 3860Higher by 420 mAltitude on night 5: 4410Higher by 550 mToo fast: plan a rest dayNights too fast: 2

The line before = altitude at the end of each round makes tonight the “night before” for the next round. Other wordings of the messages are fine.

i. and ii. A SyntaxError, on line 3:

  File "main.py", line 3    if porters = 0:       ^^^^^^^^^^^SyntaxError: invalid syntax. Maybe you meant '==' or ':=' instead of '='?

One = sets a variable; it can’t ask a question. An if needs a comparison, and “is it equal?” is two equals signs, ==. Python found the mistake before running anything, so it never asked for the porters. (:= is something else, not used in this course.)

iii. Use == on line 3:

porters = int(input("How many porters? "))pay = porters * 2000if porters == 0:    print("No porters today.")print("Pay for the day: Rs", pay)

How many porters? 3Pay for the day: Rs 6000

iv.

One good page (yours will be different):

<!DOCTYPE html><html lang="en">  <head>    <meta charset="utf-8">    <meta name="viewport" content="width=device-width, initial-scale=1">    <title>Ghorepani in Spring</title>    <link rel="stylesheet" href="style.css">  </head>  <body>    <h1>Ghorepani in Spring</h1>    <p>Ghorepani is a village in Myagdi district, at about 2,860 meters. In Chaitra and Baisakh, the forests around it are red and pink with rhododendron, Nepal’s national flower.</p>    <h2>Things to do</h2>    <ol>      <li>Climb Poon Hill before dawn to watch the sunrise</li>      <li>Walk through the flowering rhododendron forest</li>      <li>Look out over the Dhaulagiri and Annapurna mountains</li>    </ol>    <img src="rhododendrons.jpg" alt="A hillside of rhododendron trees covered in red and pink flowers">  </body></html>

body {  font-family: sans-serif;  margin: 16px;} h1 {  color: #9b1b30;} img {  max-width: 100%;}

The max-width: 100% rule keeps the photo inside a phone’s screen.

• i.Each night must be compared with the night before, so after a night is checked, its altitude becomes before for the next one. Without the line, before would stay 2,860 m, the start: every night would be compared with the start, so the rest day at Namche would show 580 m higher and be called too fast.
• ii.A name that says what the variable holds makes the program easy to read and check, for the teacher, a friend, or yourself a month later; p and x say nothing. A variable’s name can’t have a space in it (Python would read too fast as two names side by side), so the underscore joins the words into one name.
• iii.The page’s text, headings and list, but without its CSS styles and without the photo (at most its alt text). The style sheet and the photo are separate files: index.html only names them (href="style.css", src="rhododendrons.jpg"), and the browser looks for them beside the page. She needs all three files, in the same folder.