{
  "title": "Collection of Data - Grade 9 CBSE",
  "total_questions": 100,
  "questions": [
    {"id": 1, "difficulty": "easy", "question": "What is data collection?", "options": {"A": "Analyzing data", "B": "Gathering information", "C": "Organizing data", "D": "Presenting data"}, "correct_answer": "B"},
    {"id": 2, "difficulty": "easy", "question": "Data collected firsthand is called:", "options": {"A": "Secondary data", "B": "Primary data", "C": "Tertiary data", "D": "Processed data"}, "correct_answer": "B"},
    {"id": 3, "difficulty": "easy", "question": "Which is a source of primary data?", "options": {"A": "Newspaper", "B": "Survey you conduct", "C": "Textbook", "D": "Website"}, "correct_answer": "B"},
    {"id": 4, "difficulty": "easy", "question": "Data from published sources is:", "options": {"A": "Primary data", "B": "Secondary data", "C": "Raw data", "D": "Experimental data"}, "correct_answer": "B"},
    {"id": 5, "difficulty": "easy", "question": "A questionnaire is used for:", "options": {"A": "Data analysis", "B": "Data collection", "C": "Data presentation", "D": "Data organization"}, "correct_answer": "B"},
    {"id": 6, "difficulty": "easy", "question": "Which method collects data by asking questions?", "options": {"A": "Observation", "B": "Survey", "C": "Experiment", "D": "All of these"}, "correct_answer": "B"},
    {"id": 7, "difficulty": "easy", "question": "Observation method involves:", "options": {"A": "Asking questions", "B": "Watching and recording", "C": "Conducting tests", "D": "Reading books"}, "correct_answer": "B"},
    {"id": 8, "difficulty": "easy", "question": "Census collects data from:", "options": {"A": "Some people", "B": "All people", "C": "No people", "D": "Only adults"}, "correct_answer": "B"},
    {"id": 9, "difficulty": "easy", "question": "Sample collects data from:", "options": {"A": "Everyone", "B": "A part of population", "C": "No one", "D": "Only children"}, "correct_answer": "B"},
    {"id": 10, "difficulty": "easy", "question": "Which is NOT a data collection method?", "options": {"A": "Survey", "B": "Observation", "C": "Guessing", "D": "Experiment"}, "correct_answer": "C"},
    {"id": 11, "difficulty": "easy", "question": "Primary data is usually:", "options": {"A": "More reliable", "B": "Less reliable", "C": "Already processed", "D": "From books"}, "correct_answer": "A"},
    {"id": 12, "difficulty": "easy", "question": "Secondary data is:", "options": {"A": "Collected by you", "B": "Collected by others", "C": "Never reliable", "D": "Always wrong"}, "correct_answer": "B"},
    {"id": 13, "difficulty": "easy", "question": "A good questionnaire has:", "options": {"A": "Clear questions", "B": "Confusing questions", "C": "No questions", "D": "Only yes/no"}, "correct_answer": "A"},
    {"id": 14, "difficulty": "easy", "question": "Which collects numerical data?", "options": {"A": "Height measurement", "B": "Favorite color", "C": "Opinion", "D": "Feelings"}, "correct_answer": "A"},
    {"id": 15, "difficulty": "easy", "question": "Which collects categorical data?", "options": {"A": "Age", "B": "Weight", "C": "Gender", "D": "Height"}, "correct_answer": "C"},
    {"id": 16, "difficulty": "easy", "question": "Data about quantities is:", "options": {"A": "Qualitative", "B": "Quantitative", "C": "Both", "D": "Neither"}, "correct_answer": "B"},
    {"id": 17, "difficulty": "easy", "question": "Data about qualities is:", "options": {"A": "Qualitative", "B": "Quantitative", "C": "Both", "D": "Neither"}, "correct_answer": "A"},
    {"id": 18, "difficulty": "easy", "question": "Population means:", "options": {"A": "Some members", "B": "All members", "C": "No members", "D": "Only males"}, "correct_answer": "B"},
    {"id": 19, "difficulty": "easy", "question": "Sample should be:", "options": {"A": "Biased", "B": "Representative", "C": "Small only", "D": "Large only"}, "correct_answer": "B"},
    {"id": 20, "difficulty": "easy", "question": "Reliable data is:", "options": {"A": "Trustworthy", "B": "Wrong", "C": "Guessed", "D": "Made up"}, "correct_answer": "A"},
    
    {"id": 21, "difficulty": "medium", "question": "You want to know favorite sports in class. Best method?", "options": {"A": "Observation", "B": "Survey", "C": "Experiment", "D": "Census"}, "correct_answer": "B"},
    {"id": 22, "difficulty": "medium", "question": "To study plant growth, best method?", "options": {"A": "Survey", "B": "Observation", "C": "Questionnaire", "D": "Interview"}, "correct_answer": "B"},
    {"id": 23, "difficulty": "medium", "question": "Collecting data from all students in school is:", "options": {"A": "Sample", "B": "Census", "C": "Survey", "D": "Experiment"}, "correct_answer": "B"},
    {"id": 25, "difficulty": "medium", "question": "Which gives primary data? A) Weather data from app B) Measuring your height C) Reading textbook D) Watching news", "options": {"A": "A", "B": "B", "C": "C", "D": "D"}, "correct_answer": "B"},
    {"id": 26, "difficulty": "medium", "question": "Data from government website is:", "options": {"A": "Primary", "B": "Secondary", "C": "Tertiary", "D": "Raw"}, "correct_answer": "B"},
    {"id": 27, "difficulty": "medium", "question": "To know TV watching habits, method?", "options": {"A": "Survey", "B": "Observation", "C": "Both A and B", "D": "Neither"}, "correct_answer": "C"},
    {"id": 28, "difficulty": "medium", "question": "Which is quantitative data?", "options": {"A": "Eye color", "B": "Test scores", "C": "Favorite food", "D": "Religion"}, "correct_answer": "B"},
    {"id": 29, "difficulty": "medium", "question": "Which is qualitative data?", "options": {"A": "Age in years", "B": "Height in cm", "C": "Blood type", "D": "Weight in kg"}, "correct_answer": "C"},
    {"id": 30, "difficulty": "medium", "question": "Random sampling ensures:", "options": {"A": "Bias", "B": "No bias", "C": "Only rich people", "D": "Only educated"}, "correct_answer": "B"},
    {"id": 31, "difficulty": "medium", "question": "A biased sample:", "options": {"A": "Represents all", "B": "Does not represent all", "C": "Is always good", "D": "Is never used"}, "correct_answer": "B"},
    {"id": 32, "difficulty": "medium", "question": "Collecting data on car colors in parking is:", "options": {"A": "Survey", "B": "Observation", "C": "Experiment", "D": "Interview"}, "correct_answer": "B"},
    {"id": 33, "difficulty": "medium", "question": "Asking 50 of 200 students is:", "options": {"A": "Census", "B": "Sample", "C": "Population", "D": "Experiment"}, "correct_answer": "B"},
    {"id": 34, "difficulty": "medium", "question": "Primary data advantage:", "options": {"A": "Cheaper", "B": "Faster", "C": "More accurate for purpose", "D": "Already available"}, "correct_answer": "C"},
    {"id": 35, "difficulty": "medium", "question": "Secondary data advantage:", "options": {"A": "Time-consuming", "B": "Costly", "C": "Quick availability", "D": "Always perfect"}, "correct_answer": "C"},
    {"id": 36, "difficulty": "medium", "question": "Good questionnaire avoids:", "options": {"A": "Clear questions", "B": "Leading questions", "C": "Short questions", "D": "Relevant questions"}, "correct_answer": "B"},
    {"id": 37, "difficulty": "medium", "question": "Which method for testing new medicine?", "options": {"A": "Survey", "B": "Experiment", "C": "Observation", "D": "Census"}, "correct_answer": "B"},
    {"id": 38, "difficulty": "medium", "question": "Collecting rainfall data daily is:", "options": {"A": "Observation", "B": "Survey", "C": "Experiment", "D": "Sample"}, "correct_answer": "A"},
    {"id": 39, "difficulty": "medium", "question": "Data collected wrongly is:", "options": {"A": "Reliable", "B": "Unreliable", "C": "Valid", "D": "Useful"}, "correct_answer": "B"},
    {"id": 40, "difficulty": "medium", "question": "To know average income in city, use:", "options": {"A": "Census of all", "B": "Sample survey", "C": "Both possible", "D": "Neither"}, "correct_answer": "C"},
    {"id": 41, "difficulty": "medium", "question": "Primary data collection is:", "options": {"A": "Always easy", "B": "Sometimes difficult", "C": "Never needed", "D": "Always wrong"}, "correct_answer": "B"},
    {"id": 42, "difficulty": "medium", "question": "Secondary data may have:", "options": {"A": "Your control", "B": "No control over quality", "C": "Always perfect", "D": "No errors"}, "correct_answer": "B"},
    {"id": 43, "difficulty": "medium", "question": "Which needs permission?", "options": {"A": "Observing birds", "B": "Survey in school", "C": "Both need permission", "D": "Neither needs"}, "correct_answer": "B"},
    {"id": 44, "difficulty": "medium", "question": "Data about temperatures is:", "options": {"A": "Qualitative", "B": "Quantitative", "C": "Categorical", "D": "Descriptive"}, "correct_answer": "B"},
    {"id": 45, "difficulty": "medium", "question": "Data about satisfaction level is:", "options": {"A": "Quantitative", "B": "Qualitative", "C": "Numerical", "D": "Measurable"}, "correct_answer": "B"},
    {"id": 46, "difficulty": "medium", "question": "Which sampling method is fair?", "options": {"A": "Random", "B": "Only friends", "C": "Only boys", "D": "Only tall people"}, "correct_answer": "A"},
    {"id": 47, "difficulty": "medium", "question": "Pilot survey is:", "options": {"A": "Main survey", "B": "Trial survey", "C": "No survey", "D": "Final survey"}, "correct_answer": "B"},
    {"id": 48, "difficulty": "medium", "question": "Closed-ended questions have:", "options": {"A": "Fixed options", "B": "Open answers", "C": "No answers", "D": "Long essays"}, "correct_answer": "A"},
    {"id": 49, "difficulty": "medium", "question": "Open-ended questions allow:", "options": {"A": "Choice from options", "B": "Free response", "C": "No response", "D": "Only yes/no"}, "correct_answer": "B"},
    {"id": 50, "difficulty": "medium", "question": "Which is better for large population?", "options": {"A": "Census", "B": "Sample", "C": "Both same", "D": "Neither"}, "correct_answer": "B"},
    {"id": 51, "difficulty": "medium", "question": "Data collected personally is:", "options": {"A": "Always correct", "B": "May have errors", "C": "Never useful", "D": "Automatically processed"}, "correct_answer": "B"},
    {"id": 52, "difficulty": "medium", "question": "Which ensures data quality?", "options": {"A": "Careful collection", "B": "Random guessing", "C": "Copying others", "D": "Making up data"}, "correct_answer": "A"},
    {"id": 53, "difficulty": "medium", "question": "Collecting data on phone usage by watching is:", "options": {"A": "Survey", "B": "Observation", "C": "Experiment", "D": "Interview"}, "correct_answer": "B"},
    {"id": 54, "difficulty": "medium", "question": "Interview method involves:", "options": {"A": "Written questions", "B": "Face-to-face questions", "C": "No interaction", "D": "Only observing"}, "correct_answer": "B"},
    {"id": 55, "difficulty": "medium", "question": "Mailed questionnaire is:", "options": {"A": "Interview", "B": "Survey", "C": "Observation", "D": "Experiment"}, "correct_answer": "B"},
    {"id": 56, "difficulty": "medium", "question": "Which method is cheapest?", "options": {"A": "Personal interview", "B": "Telephone survey", "C": "Mailed questionnaire", "D": "Direct observation"}, "correct_answer": "C"},
    {"id": 57, "difficulty": "medium", "question": "Which gives quick results?", "options": {"A": "Mailed survey", "B": "Telephone survey", "C": "Observation over time", "D": "Long experiment"}, "correct_answer": "B"},
    {"id": 58, "difficulty": "medium", "question": "Data from experiment is usually:", "options": {"A": "Primary", "B": "Secondary", "C": "Tertiary", "D": "Not reliable"}, "correct_answer": "A"},
    {"id": 59, "difficulty": "medium", "question": "Which needs trained people?", "options": {"A": "Simple observation", "B": "Complex experiment", "C": "Both need training", "D": "Neither needs"}, "correct_answer": "B"},
    {"id": 60, "difficulty": "medium", "question": "Data collection first step:", "options": {"A": "Define objective", "B": "Analyze data", "C": "Present results", "D": "Draw graphs"}, "correct_answer": "A"},
    {"id": 61, "difficulty": "medium", "question": "Before collecting data, we need:", "options": {"A": "Clear purpose", "B": "Random numbers", "C": "Fancy paper", "D": "Many people"}, "correct_answer": "A"},
    {"id": 62, "difficulty": "medium", "question": "Which affects data quality?", "options": {"A": "Collection method", "B": "Weather", "C": "Time of day", "D": "All of these"}, "correct_answer": "D"},
    {"id": 63, "difficulty": "medium", "question": "Sample size should be:", "options": {"A": "Very small", "B": "Very large", "C": "Adequate", "D": "Doesn't matter"}, "correct_answer": "C"},
    {"id": 64, "difficulty": "medium", "question": "Stratified sampling divides population into:", "options": {"A": "Random groups", "B": "Similar groups", "C": "Different groups", "D": "No groups"}, "correct_answer": "B"},
    {"id": 65, "difficulty": "medium", "question": "Systematic sampling selects:", "options": {"A": "Every nth item", "B": "Only first items", "C": "Only last items", "D": "Random items"}, "correct_answer": "A"},
    {"id": 66, "difficulty": "medium", "question": "Convenience sampling uses:", "options": {"A": "Easily available units", "B": "Random units", "C": "All units", "D": "No units"}, "correct_answer": "A"},
    {"id": 67, "difficulty": "medium", "question": "Which sampling is least reliable?", "options": {"A": "Random", "B": "Stratified", "C": "Convenience", "D": "Systematic"}, "correct_answer": "C"},
    {"id": 68, "difficulty": "medium", "question": "Primary data is collected for:", "options": {"A": "Specific purpose", "B": "General purpose", "C": "No purpose", "D": "Others' purpose"}, "correct_answer": "A"},
    {"id": 69, "difficulty": "medium", "question": "Secondary data was collected for:", "options": {"A": "Your purpose", "B": "Someone else's purpose", "C": "No purpose", "D": "Future purpose"}, "correct_answer": "B"},
    {"id": 70, "difficulty": "medium", "question": "Data reliability means:", "options": {"A": "Consistency", "B": "Beauty", "C": "Length", "D": "Color"}, "correct_answer": "A"},
    {"id": 71, "difficulty": "medium", "question": "Data validity means:", "options": {"A": "Measures what should", "B": "Looks good", "C": "Is expensive", "D": "Is old"}, "correct_answer": "A"},
    {"id": 72, "difficulty": "medium", "question": "Which method for historical data?", "options": {"A": "Survey", "B": "Records study", "C": "Experiment", "D": "Observation"}, "correct_answer": "B"},
    {"id": 73, "difficulty": "medium", "question": "Collecting data secretly is:", "options": {"A": "Always good", "B": "Unethical", "C": "Recommended", "D": "Necessary"}, "correct_answer": "B"},
    {"id": 74, "difficulty": "medium", "question": "Informed consent means:", "options": {"A": "People know and agree", "B": "People don't know", "C": "No consent needed", "D": "Forced participation"}, "correct_answer": "A"},
    {"id": 75, "difficulty": "medium", "question": "Which method for customer feedback?", "options": {"A": "Experiment", "B": "Feedback form", "C": "Observation", "D": "Census"}, "correct_answer": "B"},
    {"id": 76, "difficulty": "medium", "question": "Data about product quality is often:", "options": {"A": "Quantitative", "B": "Qualitative", "C": "Both possible", "D": "Neither"}, "correct_answer": "C"},
    {"id": 77, "difficulty": "medium", "question": "Which is discrete data?", "options": {"A": "Number of students", "B": "Height", "C": "Weight", "D": "Temperature"}, "correct_answer": "A"},
    {"id": 78, "difficulty": "medium", "question": "Which is continuous data?", "options": {"A": "Number of cars", "B": "Time taken", "C": "Number of books", "D": "Score in test"}, "correct_answer": "B"},
    {"id": 79, "difficulty": "medium", "question": "Data collection tools include:", "options": {"A": "Questionnaire", "B": "Thermometer", "C": "Stopwatch", "D": "All of these"}, "correct_answer": "D"},
    {"id": 80, "difficulty": "medium", "question": "Pilot survey helps:", "options": {"A": "Test questionnaire", "B": "Final analysis", "C": "Data presentation", "D": "Drawing conclusions"}, "correct_answer": "A"},
    
    {"id": 81, "difficulty": "hard", "question": "For national population data, government uses:", "options": {"A": "Sample survey", "B": "Census", "C": "Observation", "D": "Experiment"}, "correct_answer": "B"},
    {"id": 82, "difficulty": "hard", "question": "To study effect of fertilizer, method?", "options": {"A": "Survey", "B": "Experiment", "C": "Observation", "D": "Interview"}, "correct_answer": "B"},
    {"id": 83, "difficulty": "hard", "question": "Which sampling gives equal chance to all?", "options": {"A": "Simple random", "B": "Convenience", "C": "Judgment", "D": "Quota"}, "correct_answer": "A"},
    {"id": 84, "difficulty": "hard", "question": "If studying school performance, population is:", "options": {"A": "Some students", "B": "All students", "C": "Teachers only", "D": "Parents only"}, "correct_answer": "B"},
    {"id": 85, "difficulty": "hard", "question": "Representative sample means:", "options": {"A": "Similar to population", "B": "Very different", "C": "Very small", "D": "Very large"}, "correct_answer": "A"},
    {"id": 86, "difficulty": "hard", "question": "Which error occurs during collection?", "options": {"A": "Sampling error", "B": "Non-sampling error", "C": "Both", "D": "Neither"}, "correct_answer": "B"},
    {"id": 87, "difficulty": "hard", "question": "Sampling error can be reduced by:", "options": {"A": "Increasing sample size", "B": "Decreasing sample size", "C": "Using convenience sampling", "D": "Asking fewer questions"}, "correct_answer": "A"},
    {"id": 88, "difficulty": "hard", "question": "Non-response in survey causes:", "options": {"A": "Bias", "B": "Better data", "C": "No effect", "D": "Smaller sample"}, "correct_answer": "A"},
    {"id": 89, "difficulty": "hard", "question": "Which gives most accurate results?", "options": {"A": "Census", "B": "Large random sample", "C": "Small convenience sample", "D": "Very small sample"}, "correct_answer": "A"},
    {"id": 90, "difficulty": "hard", "question": "Stratified sampling is used when:", "options": {"A": "Population is homogeneous", "B": "Population has distinct groups", "C": "Sample is very small", "D": "No time available"}, "correct_answer": "B"},
    {"id": 91, "difficulty": "hard", "question": "Cluster sampling divides population into:", "options": {"A": "Homogeneous groups", "B": "Heterogeneous groups", "C": "Similar groups", "D": "No groups"}, "correct_answer": "B"},
    {"id": 92, "difficulty": "hard", "question": "Multistage sampling uses:", "options": {"A": "One stage", "B": "Multiple stages", "C": "No stages", "D": "Random stages"}, "correct_answer": "B"},
    {"id": 93, "difficulty": "hard", "question": "Quota sampling selects:", "options": {"A": "Random individuals", "B": "Specific number from each group", "C": "Everyone", "D": "No one"}, "correct_answer": "B"},
    {"id": 94, "difficulty": "hard", "question": "Snowball sampling is used for:", "options": {"A": "Hidden populations", "B": "Large populations", "C": "Easy populations", "D": "All populations"}, "correct_answer": "A"},
    {"id": 95, "difficulty": "hard", "question": "Panel study collects data:", "options": {"A": "Once", "B": "Multiple times", "C": "Never", "D": "Randomly"}, "correct_answer": "B"},
    {"id": 96, "difficulty": "hard", "question": "Cross-sectional study collects data:", "options": {"A": "Over time", "B": "At one point", "C": "Never", "D": "Multiple points"}, "correct_answer": "B"},
    {"id": 97, "difficulty": "hard", "question": "Longitudinal study collects data:", "options": {"A": "Once", "B": "Over time", "C": "Never", "D": "Randomly"}, "correct_answer": "B"},
    {"id": 98, "difficulty": "hard", "question": "Which is probability sampling?", "options": {"A": "Simple random", "B": "Convenience", "C": "Judgment", "D": "Quota"}, "correct_answer": "A"},
    {"id": 99, "difficulty": "hard", "question": "Which is non-probability sampling?", "options": {"A": "Stratified", "B": "Systematic", "C": "Cluster", "D": "Purposive"}, "correct_answer": "D"},
    {"id": 100, "difficulty": "hard", "question": "Data triangulation uses:", "options": {"A": "One method", "B": "Multiple methods", "C": "No method", "D": "Guessing"}, "correct_answer": "B"}
  ]
}