70+ Data Science Objective Type Quiz & MCQs with Answers for Interview Preparation

Introduction

If you’re preparing for a Data Science course in Gurgaon or getting ready for interviews in analytics, machine learning, or AI, this is the perfect resource. We’ve compiled 70+ carefully selected Data Science MCQs with answers to test your knowledge across Python, statistics, machine learning, and real-world data tools.

Use this list to assess your understanding, revise before an interview, or prepare for competitive exams.

 Section 1: Data Science Fundamentals

Q1. What is the first step in a Data Science project?
a) Modeling
b) Data Cleaning
c) Problem Definition
d) Data Visualization
Answer: c) Problem Definition

Q2. Which of the following is NOT part of the data science lifecycle?
a) Data Preparation
b) Deployment
c) Marketing Strategy
d) Modeling
Answer: c) Marketing Strategy

Q3. What type of data is “Temperature in Celsius”?
a) Ordinal
b) Nominal
c) Interval
d) Categorical
Answer: c) Interval

Q4. What is data wrangling?
a) Data deletion
b) Data visualization
c) Data cleaning and transforming
d) Data encryption
Answer: c) Data cleaning and transforming

Q5. What is meant by ‘Big Data’?
a) Very large emails
b) Data that fits in Excel
c) Extremely large and complex datasets
d) Zoomed-in images
Answer: c) Extremely large and complex datasets

Section 2: Python for Data Science

Q6. Which Python library is used for data manipulation?
a) NumPy
b) Matplotlib
c) Pandas
d) Seaborn
Answer: c) Pandas

Q7. What does df.head() return in Pandas?
a) First 5 columns
b) Last 5 rows
c) First 5 rows
d) Column names
Answer: c) First 5 rows

Q8. Which library is used for numerical computation in Python?
a) Scikit-learn
b) NumPy
c) Pandas
d) Matplotlib
Answer: b) NumPy

Q9. What is the output of len([1,2,3]) in Python?
a) 3
b) 4
c) 2
d) Error
Answer: a) 3

Q10. Which command is used to install Python libraries?
a) install.package()
b) python.setup()
c) pip install
d) setup install
Answer: c) pip install

Section 3: Statistics & Probability

Q11. What does standard deviation measure?
a) Central tendency
b) Spread of data
c) Mode
d) Mean
Answer: b) Spread of data

Q12. What is the range of probabilities?
a) -1 to 1
b) 0 to 1
c) 0 to ∞
d) -∞ to ∞
Answer: b) 0 to 1

Q13. What is a p-value used for?
a) Predicting stock prices
b) Testing statistical significance
c) Calculating mean
d) Encoding data
Answer: b) Testing statistical significance

Q14. What is the mean of 2, 4, 6, 8, 10?
a) 5
b) 6
c) 8
d) 4
Answer: b) 6

Q15. What type of distribution is bell-shaped?
a) Normal distribution
b) Poisson
c) Binomial
d) Uniform
Answer: a) Normal distribution

Section 4: Machine Learning Basics

Q16. Which of these is a supervised learning algorithm?
a) K-means
b) PCA
c) Linear Regression
d) DBSCAN
Answer: c) Linear Regression

Q17. What is overfitting in ML?
a) Model is too simple
b) Model performs poorly
c) Model fits noise
d) Model has no bias
Answer: c) Model fits noise

Q18. Which algorithm is best for classification?
a) Linear Regression
b) Logistic Regression
c) K-means
d) PCA
Answer: b) Logistic Regression

Q19. What does the confusion matrix evaluate?
a) Model speed
b) Accuracy of classification
c) Memory usage
d) Dataset quality
Answer: b) Accuracy of classification

Q20. What is the output of a regression model?
a) Category
b) Class
c) Continuous value
d) Text
Answer: c) Continuous value

Section 5: Data Visualization

Q21. Which library is commonly used for plots in Python?
a) NumPy
b) Seaborn
c) TensorFlow
d) NLTK
Answer: b) Seaborn

Q22. What does a box plot show?
a) Relationships
b) Mean only
c) Data distribution & outliers
d) Text classification
Answer: c) Data distribution & outliers

Q23. A heatmap is useful for?
a) Checking correlation
b) Calculating averages
c) Encoding text
d) Scaling features
Answer: a) Checking correlation

Q24. Which chart is best for time series data?
a) Pie chart
b) Bar chart
c) Line chart
d) Histogram
Answer: c) Line chart

Q25. What type of chart is ideal for showing proportions?
a) Bar chart
b) Pie chart
c) Histogram
d) Boxplot
Answer: b) Pie chart

Section 6: Feature Engineering & Model Evaluation

Q26. What is feature scaling?
a) Feature removal
b) Resizing data
c) Normalizing values
d) Deleting rows
Answer: c) Normalizing values

Q27. One-hot encoding is used for?
a) Text cleaning
b) Normalization
c) Converting categorical to numeric
d) Outlier detection
Answer: c) Converting categorical to numeric

Q28. What is a ROC curve used for?
a) Measuring regression
b) Measuring classification performance
c) Scaling data
d) Cleaning data
Answer: b) Measuring classification performance

Q29. What is cross-validation used for?
a) Avoiding overfitting
b) Increasing accuracy
c) Data cleaning
d) Plotting results
Answer: a) Avoiding overfitting

Q30. Accuracy = ?
a) TP / (TP + FN)
b) (TP + TN) / (TP + TN + FP + FN)
c) FP / FN
d) TN / TP
Answer: b) (TP + TN) / (TP + TN + FP + FN)Section 7: Deep Learning & AI

Q31. Which library is used for deep learning?
a) Pandas
b) Matplotlib
c) TensorFlow
d) Scikit-learn
Answer: c) TensorFlow

Q32. What is a neural network inspired by?
a) Animal behavior
b) Human brain
c) Computer science
d) Databases
Answer: b) Human brain

Q33. What is a perceptron?
a) A type of regression
b) A basic neural unit
c) A Python function
d) A scatter plot
Answer: b) A basic neural unit

Q34. CNN is used in:
a) Time series
b) Image processing
c) Text generation
d) Plotting
Answer: b) Image processing

Q35. RNN stands for:
a) Recurrent Neural Network
b) Rapid Numeric Net
c) Regressional Node Network
d) Random Neural Net
Answer: a) Recurrent Neural Network

Section 8: Tools & Technologies

Q36. What is Jupyter used for?
a) Presentations
b) Coding notebooks
c) Email
d) Data storage
Answer: b) Coding notebooks

Q37. Git is mainly used for?
a) Hosting websites
b) Writing blogs
c) Version control
d) Plotting data
Answer: c) Version control

Q38. What does SQL stand for?
a) Structured Query Language
b) Simple Query Language
c) Search Quick Language
d) Statement Query Logic
Answer: a) Structured Query Language

Q39. What is Tableau?
a) ML framework
b) Visualization tool
c) Neural net
d) IDE
Answer: b) Visualization tool

Q40. Which cloud is popular for data science projects?
a) Dropbox
b) AWS
c) Canva
d) Blogger
Answer: b) AWS

Section 9: Real-World Applications

Q41. Data science in finance is used for:
a) Logo designing
b) Fraud detection
c) Typing emails
d) None
Answer: b) Fraud detection

Q42. In healthcare, data science helps in:
a) Marketing
b) Diagnosis prediction
c) App design
d) None
Answer: b) Diagnosis prediction

Q43. Netflix uses data science to:
a) Generate subtitles
b) Recommend content
c) Block users
d) Upload videos
Answer: b) Recommend content

Q44. In e-commerce, data science is used for:
a) SEO
b) Personalization
c) Packaging
d) Refunds
Answer: b) Personalization

Q45. What is churn prediction?
a) Product review
b) Customer leaving prediction
c) Price estimation
d) Keyword ranking
Answer: b) Customer leaving prediction

Section 10: Miscellaneous (Q46–Q70)

Q46. Which one is an open-source data science language?
a) C#
b) Java
c) R
d) PHP
Answer: c) R

Q47. What is the file extension for a Python file?
a) .text
b) .docx
c) .py
d) .csv
Answer: c) .py

Q48. CSV stands for?
a) Column-Separated Value
b) Character-Set Value
c) Comma-Separated Values
d) Code Storage Version
Answer: c) Comma-Separated Values

Q49. What does API stand for?
a) Application Programming Interface
b) Automated Programming Integration
c) Applied Python Interface
d) Algorithm Processing Info
Answer: a) Application Programming Interface

Q50. NLP deals with:
a) Numerical data
b) Image processing
c) Text and speech
d) Databases
Answer: c) Text and speech

Q51. Which Python library is used in NLP?
a) Pandas
b) NumPy
c) NLTK
d) Seaborn
Answer: c) NLTK

Q52. What does EDA stand for?
a) Enhanced Data Approach
b) Exploratory Data Analysis
c) Excel Data Algorithm
d) Estimated Data Accuracy
Answer: b) Exploratory Data Analysis

Q53. What is batch size in deep learning?
a) Number of datasets
b) Number of epochs
c) Samples processed before model update
d) Variable name
Answer: c) Samples processed before model update

Q54. What is epoch in machine learning?
a) One cycle through dataset
b) Training break
c) Model termination
d) Time limit
Answer: a) One cycle through dataset

Q55. What does .fit() do in Scikit-learn?
a) Predict
b) Train the model
c) Clean data
d) Import libraries
Answer: b) Train the model

Q56. Which method is used for prediction in sklearn?
a) .fit()
b) .train()
c) .predict()
d) .run()
Answer: c) .predict()

Q57. Which file stores a trained model?
a) .doc
b) .h5
c) .xlsx
d) .txt
Answer: b) .h5

Q58. R2 score is used for:
a) Classification accuracy
b) Regression model evaluation
c) Scaling data
d) Data merging
Answer: b) Regression model evaluation

Q59. Data leakage means?
a) Data is corrupted
b) Data used for training leaks into testing
c) Data is lost
d) File is deleted
Answer: b) Data used for training leaks into testing

Q60. Which tool is used to store data in NoSQL?
a) MySQL
b) Oracle
c) MongoDB
d) SQLite
Answer: c) MongoDB

Q61. True or False: Python is case-sensitive.
Answer: True

Q62. What is the purpose of a histogram?
a) Count frequency
b) Show average
c) Plot regression
d) Encode labels
Answer: a) Count frequency

Q63. Which method reduces dimensionality?
a) XGBoost
b) PCA
c) K-means
d) ARIMA
Answer: b) PCA

Q64. Time series data depends on?
a) Randomness
b) Seasonality & trend
c) Static value
d) Classification
Answer: b) Seasonality & trend

Q65. Which model is used for time series forecasting?
a) ARIMA
b) KNN
c) CNN
d) LDA
Answer: a) ARIMA

Q66. What does .describe() show in Pandas?
a) Dataset structure
b) Summary statistics
c) Column names
d) Histogram
Answer: b) Summary statistics

Q67. What is the full form of IoT?
a) Input of Training
b) Internet of Things
c) Information over Time
d) Interface of Technology
Answer: b) Internet of Things

Q68. Which IDE is popular for Python coding?
a) Photoshop
b) Jupyter
c) Canva
d) Notepad
Answer: b) Jupyter

Q69. Tokenization is a part of?
a) CNN
b) NLP
c) Regression
d) EDA
Answer: b) NLP

Q70. What is bias in ML?
a) Correct prediction
b) Error due to assumptions
c) Good fit
d) Accuracy increases
Answer: b) Error due to assumptions

 Conclusion

These 70+ Data Science MCQs with answers are a great resource to practice, revise, and prepare for interviews or certifications. Whether you’re upskilling or joining a Data Science course in Gurgaon, mastering these questions will boost your confidence.

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