Students must start practicing the questions from CBSE Sample Papers for Class 11 Computer Science with Solutions Set 7 are designed as per the revised syllabus.
CBSE Sample Papers for Class 11 Computer Science Set 7 with Solutions
Time Allowed: 3 hours
Maximum Marks: 70
General Instructions:
- All questions are compulsory.
- Attempt all parts of each question
- Internal choices are given, choose any one of them.
Question 1.
(a) Which program controls particular type of hardware connected to a computer? [1]
(A) Compiler
(B) Interpreter
(C) Device Driver
(D) Source Program
Answer:
(C) Device Driver
Explanation:
A device driver is a special kind of software program that controls a specific hardware device attached to a computer.
(b) A list must always be homogenous. (True/False) [1]
Answer:
False
(c) Which exception raised in case of failure of attribute reference or assignment? [1]
(A) AttributeError
(B) EOFError
(C) ImportError
(D) AssertionError
Answer:
(A) AttributeError
Explanation:
AttributeError: Raised in case of failure of attribute reference or assignment.
(d) ………………………… errors occur after interpreter interprets the code and computer begins to execute the code. [1]
(A) Syntax
(B) Runtime
(C) Exception
(D) Debugging
Answer:
(B) Runtime
(e) In if-elif-else statement, the control flows from bottom to top. (True/false) [1]
Answer:
False
(f) Write a note on print() statement. [2]
Answer:
print() communicates the program’s result to the end user. It evaluates the expression before printing it on the monitor.
print () moves to the next line after printing one statement.
>>>print( 4+6)
10
To print in the same line we can use comma’s eg. print (‘1, Love, Pvthon)
Output
I Love Python
(g) How does a spyware aid identity theft? [2]
Answer:
A spyware is a software installed in a target computer to monitor its user’s data, computing habits and keystrokes, As the user enters some personal information on his computer, the keystrokes are recorded and sent to the cyber thief. This cyber thief in turn sells this information to someone else or uses it himself to steal the identity of the user
(h) Given String strl=”Honesty is the best policy” [5]
1. What will be the output of following code? L=len(strl) print(L)
(A) 22
(B) 26
(C) 25
(D) 24
Answer:
(B) 26
Explanation:
len() function returns the number of items in an ohect. When the ohect is a string, the len() function returns the number of characters in the string.
2. What will be the output of following code?
sub=strl[:5]
print(sub)
(A) Hones
(B) Honest
(C) Honesty
(D) Error
Answer:
(A) Hones
3. What will be the output of following code? print(strl[2:8])
(A) onesty
(B) nesty i
(C) nesty is
(D) nesty
Answer:
(D) nesty
Explanation:
Concept of slicing is used in this question. In string sLicing,the output is the substring starting from the first given index position i.e 2 to one less than the second given index position i.e.
(8-1=7) of the given string str1.
4. Which of the following will result in an error? strl=”python”
(A) print(str1[2])
(B) str[1] = “x”
(C) print(str1[0:9])
(D) Both (B) and (C)
Answer:
(B) str[1] = “x”
Explanation:
Strings are immutable. So, new values cannot be assigned at any index position in a string.
5. Index value in String should be of type ………………
(A) Float
(B) Integer
(C) String
(D) Boolean
Answer:
(B) Integer
Question 2.
(a) Variables in Python do not have fixed memory locations. (True/False) [1]
Answer:
True
(b) The ……………… data type allows only True/False values: [1]
(A) bool
(B) Boolean
(C) Int
(D) None
Answer:
(B) Boolean
(c) What will be the output of the following expression?
print((2<10) and (10<2) or (3 < 8) and not 3<-3) [2]
Answer:
Output: True
(d) Anita read an article in today’s newspaper about GOI’s digital India program. But looking around in the society she found that there are still many people who are too far from the reaches of technology. Can you explain two reasons for this. [2]
Answer:
The two reasons for technology being out of reach of many are:
- Gender issues: both genders are not given equal opportunities to learn technology.
- Specially abeled people are not able to learn technology due to lack of special aids and teachers for them.
(e) (i) How will you swap the values of 2 variables in Python? [2]
(ii) Why python is a Cross-platform Language? [1]
(iii) Write a Python program to print “Hello”. [1]
Answer:
(i) If X, Y = 25, 50 then the statement print(X, Y) will print result as 25 50. Now if you want to swap values of X and Y, just need to write: X, Y = Y, X print(X, Y). Thus, now the result will be 50 25.
(ii) Python is a Cross- platform language as it can run equally on variety of platforms like Windows, Linux, Unix, Smart Phones etc.
(iii) print(“Hello”)
Question 3.
(a) ……………… has minimum length size in bytes. [1]
Answer:
bool
(b) What features of word processor make them very useful ? [2]
Answer:
A word processor is used to type in text and enhance its usefulness using the following features.
- Word processors provide variety of fonts and print styles.
- Information can be saved for later use
- A Document can be formatted in various styles to improve its looks and presentation .
- We can edit and check our document for spelling and grammatical errors.
- Changes made in the document can be tracked.
- Mail merge can be used to send copies of the same mail to multiple recipients with little or n
(c)(i) Explain the following: [2]
1. Digital certificate
2. Digital signatures
(ii) Write two ways to prevent phishing. [1]
Answer:
(i) 1. Digital certificates: Digital certificates are specially formatted digital information issued to website. It is used to verify the identity of the message sender.
2. Digital signatures: Digital signatures are a way of authenticating the identity of digital information sender filtering is done on the basis of digital certificates and digital signatures.
(ii) Ways to prevent phishing:
- Don’t open emails from unknown sources or click on links embedded in suspect messages
- Check the security guidelines of website.
Question 4.
(a) A loop that never ends is called as an infinite loop. (True/False) [1]
Answer:
True
(b) Find the errors and rewrite the correct statements. [2]
(i) list1 = (55)
(ii) list2 = 4,5,6,7, 8,9
Answer:
The corrected statements are:
(a) list1 = [55]
(b) list2 = [4,5,6,7,8,9]
(c) (i) Define debugging.
(ii) Name the Python’s source code debugger.
(iii) Define exception.
(iv) How many else clauses can be used in if block?
Answer:
i. Debugging is the process of finding errors in a program.
ii. Pdb
iii. Exception is an error that occurs during execution of a program.
iv. only one.
Question 5.
(a) Draw a flowchart to calculate area of a triangle when its three sides are given [3]
Answer:
Commonly Made Error:
The student should make use of accurate symbols.
Answering Tip:
Area of triangle can be calculated using the formula area= (s.(s-a).(s-b).(s-c)½.
(b) Explain main-memory management. [4]
OR
Explain the following:
(i) Mouse
(ii) Trackball
(ii) Scanner
(iv) Plotter
Answer:
(b) Primary-memory or Main-memory is a large array of words or bytes. Each word or byte has its own address. Main memory provides storage that can be accessed directly by the CPU. That is, to execute a program, it(program) must be in the main memory. The major activities of an operating system in regard to memory management are:
1. Keep track of which part of memory are currently being used and by whom.
2. Decide which process are loaded into the memory when memory space becomes available.
3. Allocate and de-allocate memory spaces as needed. [4]
OR
(i) Mouse: The mouse is an input device that usually contains one or two buttons. As a user moves the mouse on a flat surface, the mouse controls the cursor movement on the screen. When the user presses one of the buttons, the mouse either marks a place on the screen or makes selection from data or menu on the screen. A mouse has a sphere on its underside. This rotates as the mouse is moved along a flat surface.
(ii) Trackball: A Trackball is a pointing device almost like a mouse turned upside down. The user controls the cursor on the screen by rolling a plastic ball with a fingertip or wrist. To execute commands with a Trackball, one or more buttons are pressed, much in the same way as is done with a mouse. The cursor can be moved around on the screen by rolling the ball with a thumb or finger.
(iii) Scanner: Scanner is an input device. It is also called Optical Reader or Digital Scanner. It scans or reads text and picture printed on a paper and enters them directly into the computer memory. The advantage of a scanner is that the user needs not type the input data in. This is a lust and accurate method for entering data into the computer. The scanner takes electronic images, of text or pictures from the paper it breaks each image into light and dark dots and stores them into the computer memory in machine codes. Scanned text can be edited by OCR software. Optical Character Recognition (OCR) software translates the scanned document into text that can be edited.
(iv) Plotter: Plotter is a special output device, which is used to produce high quality, perfectly proportional hard copy output. Plotters are designed to produce large drawings or images such as construction plans for buildings or blue prints for mechanical devices. Plotters have been used in automotive and aircraft design, topological surveys, architectural layouts and other similar complex drafting jobs.
A plotter is composed of a pen, a move-able carriage, a drum and a holder for chart paper. Both the pen and the paper can move up and down and back and forth. This permits very detailed drawings. Some plotter having colored pens can make colored drawings also.
Question 6.
(a) Write a program that asks two people for their names; stores the names in variables called namel and name2; says hello to both of them. [2]
Answer:
name1 = input("Enter name")
name2 = input("Enter name")
print("Hello"||, name1)
print ("Hello"||, name2)
(b) The following program is not giving the intended output. Input given is 4 and the expected output is 16. Find the error. [2]
N = input(“Enter number”)
S = N *N
print( S)
OR
Write a program to calculate in how many days a work will be completed by three persons A, B an C together. A, B, C take x days, y days and z days respectively to do the job alone. The formula to calculate the number of days if they work together is xyz/(xy + yz + xz) days where x, y an z are given as input to the program. [2]
Answer:
The number is being treated as a string. So, if we convert it to integer we will get the desired output.
N = int (input(“Enter number “))
S = N*N
print(s)
OR
x = int(input(’Enter the number of days required by A: ‘))
y = int(input(’Enter the number of days required by B: ‘))
z = int(input(’Enter the number of days required by C: ‘))
toget = (x * y * z)/(x*y + y*z + x*z)
days = round(toget, 2)
print(‘Total time taken to complete work if A, B and C work together: ‘, days)
(c) Match the columns:
| (a) Nested loop () | (i) Never ending loop |
| (b) Infinite loop () | (ii) Indefinite loop |
| (c) for loop () | (iii) Loop inside another loop |
| (d) while loop () | (iv) Terminating the loop |
| (e) break () | (v) Definite loop |
Answer:
a. (iii)
b. (i)
c. (v)
d. (ii)
e. (iv)
Question 7.
(a) …………………………… is a potential violation from security. [1]
Answer:
Threat
(b)
(i) How is the Linkedln different from Facebook? [4]
(ii) List some uses of Facebook.
OR
What is PRO ? What are the impacts of e-waste on the environment?
Answer:
(i)
| 1. LinkedIn is used by professionals. | Facebook can be used by anyone above the age of 13 years. |
| 2. A user can create profiles like resumes with experience, education and other achievements. | User profile of a Facebook gives details of personal likings and disliking. |
(ii) Some uses of Facebook are:
- Chat with friends
- See updates and post from friends
- Share photos and videos from friends.
- Share information on your profile page
- Invite friends to join groups and events
- Connect with business and celebrities.
- Connect your account with other sites
OR
PRO or Producer Responsibility Organization has been authorized and financed collectively by producers to share the responsibility for collection and channelization of e-waste generated from the end-life of products to ensure environmentally sound management of e-waste.
- It pollutes air through the emission of gases and fumes in the atmosphere.
- It pollutes soil when dumped into the landfills by seeping harmful chemicals into the soil.
- It pollutes the water by releasing the particles into the water of sea, rivers, ponds or lakes.
Question 8.
(a) Read the following text and answer the following questions on the basis of the same:
Software is a set of instructions, data, or programs used to operate a computer and execute specific tasks. In simpler terms, software tells a computer how to function. It’s a generic term used to refer to applications, scripts, and programs that run on devices such as PCs, mobile phones, tablets, and other smart devices. Software contrasts with hardware, which is the physical aspects of a computer that perform the work. There are two basic types:
System software to provide core functions such as operating systems, disk management, utilities, hardware management and other operational necessities.
Application software (applications or apps) helps users perform tasks. Office productivity suites, data management software, media players and security programs are examples. Applications also refer to web and mobile applications like those used to shop on Amazon.com, socialize with Facebook or post pictures to Instagram. [3]
1. A part of computer system that consist of data on computer instructions:
(A) Software
(B) Chip
(C) Hardware
(D) DOS
Answer:
(A) Software
Explanation:
A part of computer system that consists of data on computer instructions is called software. In simpler terms, software tells a computer how to function.
2. Special purpose software is:
(A) Application software
(B) System software
(C) Utility software
(D) None of the above
Answer:
(A) Application software
Explanation:
Application software are categories in three parts:
(i) specific purpose application software.
(ii) General purpose Application software.
(iii) Customised application software.
3. A system program that set-up executable program in main memory ready for execution is called:
(A) Text editor
(B) Compiler
(C) Linker
(D) Loader
Answer:
(D) Loader
Explanation:
A loader is the part of an operating system that is responsible for loading programs and libraries.
(b) siddhant today read about Python modules. Tell him what apart from functions a Python module can contain ? [1]
(A) classes
(B) statements
(C) variables of all types
(D) all of these
Answer:
(D) all of these
(c) Pranav is president of Environmental club of his school. They are planning to put up posters in the school listing steps for e-waste management, write any 3 points they should give in the poster. [3]
Answer:
- Give back your e-waste to your electronic companies and drop off points
- Donate your outdated technology
- Give your electronic waste to a certified e-waste recycler.
Question 9.
(a) (i) What is the difference between indexing and slicing? [1]
(ii) Define a list. [1]
Answer:
(i) Indexing is used to obtain individual items, while slicing is used to obtain a subset of items.
(ii) A list is a changeable sequence of values which can be homogenous or heterogeneous indexed by an integer.
(b) Write the output of these codes: [2]
(i) m = 60
if m > 40 or m < 100 and m == 120
print (“I am in if”)
else:
print (“I am in else)
Answer:
(i) I am in if
(ii) m, n = 6, 18
if (m – n == 15) :
print (“Equal”)
else:
print (“Not equal”)
Answer:
(ii) Not Equal