Class 12 Introduction to Big Data and Data Analytics Mock Test (CBSE)

Topics in Introduction to Big Data and Data Analytics

• What is big data
• Types of big data
• Characteristics of big data: the Vs
• Big data analytics
• Working of big data analytics
• Mining data streams
• Future of big data analytics

Introduction to Big Data and Data Analytics practice questions with answers

1. Q1Multiple choice·1 mark
   A shop's sales records have about 500 rows per month and can be opened in ordinary spreadsheet software. Why is this dataset not considered big data?

   1. (a)The records are kept on paper rather than in a computer
   2. (b)The records contain only numerical values
   3. (c)Sales records can never be used to take business decisions
   4. (d)Its volume and speed are small enough for ordinary tools, so it is not beyond traditional handling
   Show answer and step marks

   1. Correct option: (d) Its volume and speed are small enough for ordinary tools, so it is not beyond traditional handling+1

   Answer: (d)
2. Q2Multiple choice·1 mark
   Which statement best describes the future of big data analytics?

   1. (a)Analysing data only after it has been collected in a single spreadsheet
   2. (b)Real-time analysis of streaming data, with automated models giving quick insights
   3. (c)Stopping data collection once a dataset becomes larger than a few gigabytes
   4. (d)Using only manual reading of old records to take every business decision
   Show answer and step marks

   1. Correct option: (b) Real-time analysis of streaming data, with automated models giving quick insights+1

   Answer: (b)
3. Q3Short answer·2 marks
   A hill station tourism app collects two kinds of data from visitors during a trip. Classify each as structured, semi-structured or unstructured data. (a) Visit log entries, each carrying tags such as place and time, where different entries hold different numbers of fields. [1] (b) Photographs of the valley uploaded by visitors, stored as image files. [1]
   Show answer and step marks

   1. (a) Semi-structured: the entries carry tags but do not follow one fixed set of columns.+1
   2. (b) Unstructured: image files have no predefined fields or tabular format.+1

   Answer: (a) Semi-structured; (b) Unstructured
4. Q4Short answer·3 marks
   A streaming platform records the number of viewing sessions each day, in lakh. The figures for five consecutive days are 4.2, 4.6, 5.1, 4.9 and 5.2. (a) Calculate the mean number of daily sessions over these five days. [1] (b) Find the day on which the number of sessions rose the most over the previous day. [1] (c) Explain how the platform can use these past records to plan for the next day's demand. [1]
   Show answer and step marks

   1. (a) Sum of sessions $= 4.2 + 4.6 + 5.1 + 4.9 + 5.2 = 24.0$ lakh+0.5
   2. (a) Mean $= \frac{24.0}{5} = 4.8$ lakh sessions per day+0.5
   3. (b) Rises over the previous day: day 2 $= 0.4$, day 3 $= 0.5$, day 4 $= -0.2$, day 5 $= 0.3$+0.5
   4. (b) The greatest rise is on day 3, of 0.5 lakh+0.5
   5. (c) Past records are analysed to find the trend, which is used to forecast the next day's sessions+0.5
   6. (c) The forecast helps the platform plan server capacity and content for the expected demand+0.5

   Answer: (a) 4.8 lakh sessions per day; (b) Day 3; (c) Analysing past records to forecast next day's viewing and plan server capacity.
5. Q5Short answer·3 marks
   A smart-meter company collects electricity readings from 2 lakh homes every 15 minutes. A student examining the raw files notices that some readings appear twice and some entries are blank. After these faults are dealt with, the cleaned readings are analysed to find the evening peak-usage hours, and the results are then shown to managers as colour charts on a screen. (a) Name the stage of the analytics process in which the duplicate and blank readings are dealt with. [1] (b) Explain why this stage must be completed before the analysis stage begins. [1] (c) Identify the stage in which the peak-usage results are shown as colour charts on a screen. [1]
   Show answer and step marks

   1. (a) The stage is data cleaning (pre-processing), in which duplicate and blank readings are removed or corrected+1
   2. (b) Duplicates and blanks would distort the patterns found, so the analysis would give wrong peak-usage results+1
   3. (c) The stage is visualisation (presentation of results), in which the output is shown as charts or dashboards+1

   Answer: (a) Data cleaning (pre-processing); (b) Dirty data would produce wrong patterns and misleading analysis; (c) Visualisation.

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