Application Development - 1 · Quiz 2 · Jan 2026

**1. Identify the requested access pattern:** The app needs a quick lookup of one small fact using a student/user identifier: has this user downloaded the ticket? This naturally maps to user_id→downloaded_flag. **2. Match the data model:** A key–value store is designed for direct retrieval by key, without joining tables, traversing relationships or searching a document structure. **3. Limit the recommendation:** This is the most suitable offered store for the isolated flag lookup. The rest of a hall-ticket application can still use relational storage and access controls; an indexed RDBMS can also perform this lookup efficiently. **Answer: D — Key-value store.** A: **Incorrect:** An indexed relational table can work well, but its richer relational model is not required for the narrow flag lookup asked here. B: **Incorrect:** Document structure is unnecessary for a single keyed status value. C: **Incorrect:** Graph traversal offers no advantage for this direct identifier-to-flag access pattern. D: **Correct:** A user identifier can directly index the downloaded-status value.

**1. Identify the browser interaction:** The client needs to request or send data in the background while keeping the currently loaded page. JavaScript can update only the relevant UI afterward. **2. Match the term:** AJAX is the conventional name for this asynchronous browser–server interaction, historically using XMLHttpRequest and now also commonly implemented with fetch. The transferred data need not be XML. **Answer: D — AJAX.** A: **Incorrect:** CGI is a server-side interface for running programs, not the browser technique for partial-page asynchronous updates. B: **Incorrect:** FTP transfers files and is not the intended browser-page communication mechanism. C: **Incorrect:** SMTP transfers email rather than making interactive background web requests. D: **Correct:** AJAX enables asynchronous requests and page updates without a full reload.

**1. Read the query parameters:** The URL supplies user=Alice and role=ADMIN, so the defaults Guest and Member are not used. **2. Apply the transformations:** username.upper() becomes ALICE; role.lower() becomes admin. These transformed values are supplied to the Template placeholders name and role_type. **3. Substitute the text:** The template becomes “Hello ALICE! Your role is admin.” The placeholder name role_type does not need to be a URL parameter because it is explicitly supplied to substitute(). **Answer: D — Hello ALICE! Your role is admin..** A: **Incorrect:** role_type is provided as a substitution keyword, so it need not appear in the URL. B: **Incorrect:** The URL supplies both values, and the code also applies uppercase to the username. C: **Incorrect:** This leaves both original capitalizations unchanged, ignoring the transformations. D: **Correct:** It applies both requested transformations and substitutes the correct placeholders.

**1. Apply the decorator:** @modify replaces the name bar with wrapper, which retains access to the original multiplication function as func. **2. Trace bar(2,3):** wrapper receives p=2,q=3 and calls the original function, producing 2×3=6. **3. Apply the wrapper’s return:** It returns result+5=6+5=11. This is numeric addition, not string concatenation or multiplication by five. **Answer: B — 11.** A: **Incorrect:** The numbers are numeric, so six and five are added rather than concatenated into 56. B: **Correct:** The underlying product six is increased by five to give eleven. C: **Incorrect:** Six is the intermediate multiplication result before the wrapper adds five. D: **Incorrect:** The wrapper adds five; it does not multiply the product by five.

**1. Compute the image-transfer ceiling:** Using decimal networking units, 1 Gbps is \(10^9/8=125{,}000{,}000\) bytes/s. A 100-KB image is 100,000 bytes, allowing at most 1250 image transfers/s if other traffic is ignored. **2. Compare application throughput:** The single running application can generate only 500 pages/s. The overall rate cannot exceed either its processing capacity or the network capacity. **3. Select the bottleneck:** \(\min(500,1250)=500\) page requests/s in the given simplified model. More CPU cores do not multiply the explicitly stated single-instance capacity automatically. **Answer: D — 500.** **Convention note:** This uses the question’s simplified model in which page-processing and image-transfer ceilings are compared; HTML size, protocol overhead and other resource contention are not quantified. A: **Incorrect:** This exceeds both the stated application capacity and the estimated image-transfer ceiling. B: **Incorrect:** 1250 is the image-only network ceiling, but the app is limited to 500 pages/s. C: **Incorrect:** The application cannot generate 1000 pages/s under the supplied capacity. D: **Correct:** The application’s 500-page/s capacity is the tighter stated limit.

**1. Count request bytes:** Headers and payload total \(4+6=10\) KB, or 10,000 bytes using the stated decimal units. **2. Convert to bits:** Each request uses \(10{,}000(8)=80{,}000\) bits. A 5-Mbps link supplies 5,000,000 bits/s. **3. Divide and choose the offered integer:** \(5{,}000{,}000/80{,}000=62.5\) requests/s as an ideal average bandwidth rate. The largest offered whole number below that ceiling is 62. **Answer: B — 62.** **Convention note:** The bandwidth-derived long-run ideal rate is 62.5 requests/s. The listed answer 62 treats the result as a whole-request-per-second budget and excludes additional protocol/response overhead. A: **Incorrect:** It ignores the necessary byte-to-bit conversion and exceeds the link budget. B: **Correct:** 62 complete requests use 4,960,000 bits, below the 5-Mbps budget; 63 would exceed it in a one-second budget. C: **Incorrect:** 124 requests would require approximately twice the available bandwidth. D: **Incorrect:** 31 is below the attainable ideal ceiling and is not the maximum offered feasible count.

**1. List the competing declarations:** The element matches the p rule (blue), .text class (green), and #para ID (red). It also carries the inline declaration style="color:black". **2. Apply the cascade:** For these ordinary author declarations with no !important, the inline declaration overrides the stylesheet selector declarations. ID specificity does not override that normal inline style. **3. State the rendering:** The text “IITM BS Degree Program” appears in black. Its wording is unchanged; only the winning colour is being selected. **Answer: C — IITM BS Degree Program in black.** A: **Incorrect:** The ID rule would beat the class/type rules, but it loses to the supplied inline colour. B: **Incorrect:** The class rule does not override the ID rule or the inline declaration. C: **Correct:** The normal inline color:black declaration wins among the shown rules. D: **Incorrect:** The type-selector rule has the lowest specificity among the competing stylesheet rules and also loses to inline styling.

**1. Convert bus width:** A 64-bit transfer carries \(64/8=8\) bytes. **2. Include DDR:** At one billion clock cycles per second and two transfers per cycle, the rate is \(2\times10^9\) transfers/s. **3. Calculate bandwidth:** \(8(2\times10^9)=16\times10^9\) bytes/s, or 16 decimal GB/s. This is the theoretical bus ceiling rather than a guaranteed sustained application bandwidth. **Answer: B — 16 GigaBytes/s.** A: **Incorrect:** Eight GB/s counts only one transfer per cycle and omits DDR’s factor of two. B: **Correct:** Eight bytes per transfer times two billion transfers per second gives sixteen GB/s. C: **Incorrect:** The specification supplies two transfers per cycle, not three. D: **Incorrect:** The correct sixteen-GB/s value is explicitly offered.

**1. Recognize Flask variable syntax:** Angle brackets declare a dynamic path component. /user/id is a literal path and does not capture the value 55. **2. Check compatible converters:** /user/<int:id> accepts the integer-looking segment 55 and converts it to an integer. /user/<id> uses the default string converter, which also accepts the text “55”. **3. Check the float route precisely:** The standard Werkzeug float converter requires a decimal-form path such as 55.0. The literal integer segment 55 does not match it, even though Python could convert the string to float manually. **Answer: B, C — /user/<int:id> and /user/<id>.** A: **Incorrect:** Without angle brackets, id is a literal part of the URL rather than a variable. B: **Correct:** The int converter matches 55 and provides the handler with integer 55. C: **Correct:** The default string converter matches the nonempty segment and provides string "55". D: **Incorrect:** The standard float converter does not match the exact integer-only path /user/55; /user/55.0 is a different path.

**1. Identify the route’s shape:** /user/<name> matches one nonempty path segment after /user/. Its default converter is string, so both letters and digits are allowed. **2. Check the valid URLs:** /user/IITM supplies name="IITM" and /user/101 supplies name="101". /user/BS?id=101 matches the path with name="BS"; the query string does not change route matching. **3. Reject path mismatches:** /user/10/greet adds an unhandled segment, while /user supplies no required name segment. Neither matches this sole route. **Answer: A, B, E — **http://127.0.0.1:5000/user/IITM**; **http://127.0.0.1:5000/user/101**; **http://127.0.0.1:5000/user/BS?id=101**.** A: **Correct:** IITM is a valid single string segment and renders Welcome IITM. B: **Correct:** Digit characters also form a valid string name and render Welcome 101. C: **Incorrect:** The extra /greet segment is not included in the route. D: **Incorrect:** The required name path component is missing. E: **Correct:** The path captures BS; the unrelated query parameter does not prevent a match.

**1. Locate the assignment:** Each iteration executes {% set x = i %}, but the assignment occurs inside Jinja’s loop scope. The template does not initialize an outer x or use a namespace. **2. Follow scope exit:** The loop-local x values do not survive as an outer variable after endfor. Therefore the later {{ x }} refers to an undefined value. **3. Apply default rendering:** Flask’s ordinary Jinja undefined handling renders that missing variable as an empty string. The visible output is only “Output is:”, ignoring layout whitespace. **Answer: B — Output is:.** **Convention note:** An environment configured with StrictUndefined would raise an undefined-variable error instead. The supplied Flask setup uses the normal default undefined rendering. A: **Incorrect:** Loop assignments do not leak the final value three into the outer scope. B: **Correct:** The outside variable is undefined and renders blank under the default Jinja environment. C: **Incorrect:** The loop contains assignments, not expressions printing i on each iteration. D: **Incorrect:** Neither the loop values nor a final outer three are printed.

**1. Identify the returned collection:** getElementsByTagName("li") returns a live HTMLCollection. Initially it contains the one existing list item. **2. Apply innerHTML +=:** The script replaces the list contents with the old markup plus two new li elements. The list consequently contains App Dev-1, App Dev-2 and App dev projects. **3. Read the live length:** Because the collection tracks current matching DOM elements, lst_items.length is now three and the console prints 3. A static snapshot would behave differently. **Answer: C — 3.** A: **Incorrect:** One is the old count; the collection is live and reflects the added elements. B: **Incorrect:** Two counts only the appended items and omits the original item still in the resulting markup. C: **Correct:** The resulting document contains three li elements and the live collection reports three. D: **Incorrect:** Only two items are appended to the original one, not three.

**1. Inspect permitted methods:** @app.route("/login",methods=["POST"]) accepts POST for this handler. An ordinary browser address-bar navigation sends GET and is not permitted. **2. Inspect curl’s explicit methods:** -X GET overrides the request method even with --json, so B receives 405 Method Not Allowed. A and E explicitly send POST and reach the credentials check. **3. Inspect curl’s implicit method:** --json sends request data and selects POST when no overriding method is given, so D also uses POST. Wrong credentials in A produce the application’s “Invalid credentials...” response, not a method error. **Answer: B, C — curl -X GET --json '{"uid":"admin","pwd":"xyz"}' http://127.0.0.1:5000/login; URL request: http://127.0.0.1:5000/login.** A: **Incorrect:** It uses the allowed POST method; the wrong password affects credentials, not method permission. B: **Correct:** -X GET explicitly chooses a method not allowed by the route, yielding 405. C: **Correct:** Opening that URL normally sends GET and yields 405 for this POST-only route. D: **Incorrect:** With --json and no explicit override, curl sends POST, so the route is allowed. E: **Incorrect:** It explicitly sends POST with the expected credentials and does not produce a method error.

**1. Match the route argument:** The registered resource URL contains <int:id>, so Flask-RESTful passes an id keyword argument to the selected HTTP-method handler. The handler signature must accept it. **2. Check supported method names:** A get(self,id) method handles GET and a post(self,id) method handles POST. Either can perform the shown search when requested with its corresponding method. **3. Follow the search logic:** The valid methods compare p["id"] against the received integer, return the matching formatted product and otherwise return the not-found text. Methods missing id fail to accept the route parameter. **Answer: B, D — B and D — handlers accepting id for their respective HTTP methods.** **Convention note:** Selecting a POST handler means the client must send POST; an ordinary browser GET will not call it. The question asks which inserted implementations can work, rather than requiring both to support GET. A: **Incorrect:** post(self) lacks id, so dispatch passes an unexpected id keyword and the handler cannot run correctly. B: **Correct:** get(self,id) accepts the route argument and handles a GET lookup. C: **Incorrect:** get(self) similarly fails to accept the id supplied by the resource route. D: **Correct:** post(self,id) accepts the argument and correctly searches for a POST lookup.

**1. Read the scalar relationship:** User.profile sets uselist=False, so accessing that attribute produces one Profile object or None instead of a list. **2. Read the database restriction:** Profile.user_id is both a foreign key to User.id and unique. The uniqueness prevents two non-null profile rows from referencing the same user. **3. Combine the constraints:** This is the intended one-to-one mapping: at most one linked profile per user, and one user for a non-null linked profile. The declarations do not require every user to already have a profile. **Answer: D — One-to-One.** A: **Incorrect:** There is no many-to-many association table or collection on both sides. B: **Incorrect:** A unique user_id prevents multiple profiles from sharing one non-null user reference. C: **Incorrect:** The User side is scalar and the foreign key is unique, so it is not a collection of multiple profiles. D: **Correct:** uselist=False plus the unique foreign key implements the one-to-one mapping.