Total Pageviews

Friday, September 4, 2026

COMPUTISM LAB CLASS 7 HALF YEARLY EXAMINATION

💻
🤖
🖥️
🗼
✨ Class 7 Computer Science Examination ✨

COMPUTISM LAB CLASS 7 HALF YEARLY EXAMINATION

Term Half-Yearly Assessment

🧠
🤖
Class: 7
Max Marks: 70
Time Allowed: 2 Hours
Section A: Fill in the Blanks10 Marks
  1. SMPS stands for Switched-Mode .
  2. A modem converts digital data into signals.
  3. The main circuit board of a computer system is called the .
  4. RAM stands for Random Memory.
  5. The octal number system consists of 8 digits with the base .
  6. The hexadecimal number system includes digits from 0 to 9 and letters from A to .
  7. The term VIRUS stands for Vital Information Resources Under .
  8. A sector virus infects the boot sector of a hard drive.
  9. The tag used to insert an image in an HTML web page is .
  10. Every HTML form uses a element which begins the form structure.
Section B: Multiple Choice Questions (MCQs)20 Marks
  1. What does CPU stand for?
    • a. Central Processing Unit
    • b. Computer Power Unit
    • c. Central Program Utility
    • d. Control Processing Unit
  2. Which of these is not an external hardware device?
    • a. Keyboard
    • b. Mouse
    • c. RAM
    • d. Monitor
  3. Which device is used to scan documents optically?
    • a. Printer
    • b. Scanner
    • c. Modem
    • d. Projector
  4. A projector is an example of which type of device?
    • a. Input
    • b. Storage
    • c. Output
    • d. Processing
  5. What type of printer uses a printing head that strikes the paper ribbon directly?
    • a. Impact printer
    • b. Non-impact printer
    • c. Inkjet printer
    • d. Thermal printer
  6. What is the base of the hexadecimal number system?
    • a. 10
    • b. 8
    • c. 16
    • d. 2
  7. What is the binary equivalent of the decimal number 10?
    • a. 1110
    • b. 1010
    • c. 1001
    • d. 1100
  8. Which of the following is a valid hexadecimal number representation?
    • a. 4D2
    • b. 78H
    • c. 19G
    • d. 8Z4
  9. To convert a decimal number to binary, repeatedly divide it by which number?
    • a. 8
    • b. 10
    • c. 2
    • d. 16
  10. What does the letter 'C' represent in hexadecimal values?
    • a. 13
    • b. 12
    • c. 14
    • d. 15
  11. Which of these enters a computer without the permission or knowledge of the user?
    • a. Antivirus
    • b. Virus
    • c. Internet
    • d. Firewall
  12. Which of these looks like an antivirus but is actually a malicious program?
    • a. Quick Heal
    • b. Sweeper
    • c. Norton
    • d. McAfee
  13. Which of the following is a self-replicating program without human intervention?
    • a. Antivirus
    • b. Macro
    • c. Worm
    • d. Trojan Horse
  14. What tag is used to define table rows in HTML?
    • a. <table>
    • b. <tr>
    • c. <td>
    • d. <th>
  15. What does <input type="checkbox"> allow the user to do?
    • a. Choose multiple options
    • b. Choose only one option
    • c. Reset form
    • d. Submit form
  16. To add a caption to a table in HTML, use which tag?
    • a. <table>
    • b. <title>
    • c. <caption>
    • d. <head>
  17. To collapse table borders in CSS, which property value should be used?
    • a. border-collapse: collapse;
    • b. table-collapse: border;
    • c. collapse: border;
    • d. border: collapse;
  18. Which attribute specifies the source file path of an image in the <img> tag?
    • a. alt
    • b. src
    • c. href
    • d. name
  19. What tag is used to display a numbered list in HTML?
    • a. <ul>
    • b. <ol>
    • c. <li>
    • d. <list>
  20. Which HTML tag is used to mark text as a hyperlink?
    • a. <link>
    • b. <a> (Anchor tag)
    • c. <href>
    • d. <hyper>
Section C: Assertion-Based MCQs10 Marks
  1. Assertion (A): RAM is known as a volatile memory.
    Reason (R): Information stored in RAM is lost when you turn off the computer or power goes off.
    a) Both A and R are true, and R is the correct explanation of A.
    b) Both A and R are true, but R is not the correct explanation of A.
    c) A is true, but R is false.
    d) A is false, but R is true.
  2. Assertion (A): ROM is a non-volatile memory.
    Reason (R): ROM retains stored information even when the power has been switched off.
    a) Both A and R are true, and R is the correct explanation of A.
    b) Both A and R are true, but R is not the correct explanation of A.
    c) A is true, but R is false.
    d) A is false, but R is true.
  3. Assertion (A): The binary number system uses base 2.
    Reason (R): Binary number system consists of ten digits from 0 to 9.
    a) Both A and R are true.
    b) A is true, but R is false.
    c) A is false, but R is true.
    d) Both A and R are false.
  4. Assertion (A): A computer virus can spread via removable storage devices like flash drives.
    Reason (R): Flash drives can carry malicious files and execute AutoRun code to compromise host machines.
    a) Both A and R are true, and R is the correct explanation of A.
    b) Both A and R are true, but R is not the correct explanation of A.
    c) A is true, but R is false.
    d) A is false, but R is true.
  5. Assertion (A): Antivirus software updates its virus database frequently.
    Reason (R): Frequent updates ensure the system can detect new and different types of virus threats effectively.
    a) Both A and R are true, and R is the correct explanation of A.
    b) Both A and R are true, but R is not the correct explanation of A.
    c) A is true, but R is false.
    d) A is false, but R is true.
  6. Assertion (A): A computer worm is a self-replicating program that can travel without human action.
    Reason (R): Unlike viruses, worms do not consume network bandwidth or memory.
    a) Both A and R are true.
    b) A is true, but R is false.
    c) A is false, but R is true.
    d) Both A and R are false.
  7. Assertion (A): The <img> tag requires a closing tag like </img> in HTML.
    Reason (R): The <img> tag is an empty tag used to add images to a web page.
    a) Both A and R are true.
    b) A is true, but R is false.
    c) A is false, but R is true.
    d) Both A and R are false.
  8. Assertion (A): The action attribute in an HTML form specifies the file or script the form is submitted to.
    Reason (R): The method attribute specifies how the form information is posted (Get or Post).
    a) Both A and R are true, and R is related to form submission settings.
    b) Both A and R are false.
    c) A is true, R is false.
    d) A is false, R is true.
  9. Assertion (A): Octal number system consists of 8 digits with the base 8.
    Reason (R): Octal system takes binary digits in groups of three to make binary more compact.
    a) Both A and R are true, and R explains the reason behind the octal system.
    b) Both A and R are true, but unrelated.
    c) A is true, R is false.
    d) A is false, R is true.
  10. Assertion (A): Real-time scan in antivirus software runs continuously in the background.
    Reason (R): Real-time scan provides maximum protection by screening opened or saved files for security risks.
    a) Both A and R are true, and R is the correct explanation of A.
    b) Both A and R are true, but unrelated.
    c) A is true, R is false.
    d) A is false, but R is true.
Section D: True or False10 Marks
  1. RAM stores information permanently. (True / False)
  2. A digital camera is classified as an output device. (True / False)
  3. Binary numbers use digits from 0 to 7. (True / False)
  4. The binary system is the most commonly used number system by digital computers. (True / False)
  5. Data is an important asset for an organisation or individual. (True / False)
  6. Viruses cannot be sent as executable files (.exe) with email attachments. (True / False)
  7. A computer worm can travel without any human action. (True / False)
  8. The <img> tag must always be closed with </img>. (True / False)
  9. External links lead to a different website or web page. (True / False)
  10. The border-spacing property is used to change the distance between table cells. (True / False)
Section E: Short Answer Questions (2 Marks Each)20 Marks
  1. Differentiate between RAM and ROM in terms of usage and volatility.
  2. Differentiate between internal and external hardware with examples.
  3. What is a plotter, and how is it used?
  4. Differentiate between impact and non-impact printers.
  5. Write the use of a motherboard in a computer system.
  6. Convert all octal no into binary: 150,73,1020.
  7. Convert all decimal no into binary: 101100,1100110,101010101.
  8. Convert all decimal no into binary: 150,73,1020.
  9. What is the use of an antivirus? Give two examples.
  10. What is malware?
⭐ Best of Luck for Your Examination! Keep Learning! 🚀
Created by Bijan Krishna Paul

NEW

WEST BENGAL BOARD

CLASS 12 PYTHON MCQ ONLINE EXAMINATION

Python Output-Based • Syntax • Variables • Data Types • Operators • If-Else • For/While • Strings

মোট প্রশ্ন: ৬০   |   সময়: ৬০ মিনিট   |   পূর্ণমান: ৬০

Assertion–Reason প্রশ্ন: ২০টি

⚠️ পরীক্ষা শুরু করার পরে Full Screen চালু হবে। Full Screen থেকে বের হলে পরীক্ষা স্বয়ংক্রিয়ভাবে জমা হবে।

60:00
পরীক্ষা
👨‍🎓
🏫

🏆 পরীক্ষার ফলাফল

নাম:
বিদ্যালয়:
0 / 60
সঠিক উত্তর:
ভুল উত্তর:
উত্তর না দেওয়া:
সময়:
📋 উত্তর পর্যালোচনা

CLASS 12 PYTHON MCQ QUESTION WEST BENGAL BOARD SAMPLE PAPER 2026

AI & MACHINE LEARNING ASSESSMENT

Professional Online MCQ Examination

Wednesday, September 2, 2026

📊 Histogram Specification / Matching

📊 Histogram Specification / Matching

Match the histogram of an input image with a target image
Upload an input image and a target image.

1. Input Image

2. Target Image

3. Input Histogram

4. Target Histogram

5. Input CDF

6. Target CDF

7. Gray-Level Mapping

Input Gray Input H Input CDF Target Gray Target CDF New Map

8. New Mapped Image

9. Histogram After Mapping

10. Mapping Result

Waiting for histogram matching...

🧮 Histogram Matching Mathematics

Step 1 — Convert image to grayscale

For an RGB pixel:

Gray = 0.299R + 0.587G + 0.114B
Step 2 — Calculate histogram

For each gray level rk, count the number of pixels.

H(rk) = nk
Step 3 — Calculate probability

If N is the total number of pixels:

P(rk) = nk / N
Step 4 — Calculate input CDF
Cinput(rk) = Σ P(rj)

where j = 0 to k.

Step 5 — Calculate target CDF
Ctarget(zq) = Σ P(zj)
Step 6 — Find the matching gray level

For every input gray level, find the target gray level whose CDF is closest to the input CDF.

Find z such that Ctarget(z) ≈ Cinput(r)
Step 7 — Create the mapping
r → z

Every pixel having gray level r is replaced with the mapped gray level z.

Example
Input CDF = 0.60

Suppose the target histogram has:

Target CDF at gray 150 = 0.58 Target CDF at gray 151 = 0.61

The closest target CDF is 0.61, therefore:

Input gray level → Target gray level r → 151
Complete process
Input Image → Grayscale → Input Histogram → Input CDF → Target Histogram → Target CDF → Mapping → New Image