🤖 120+ Questions • Updated 2026

Machine Learning Multiple Choice Questions

Master Machine Learning with 120+ curated MCQs covering algorithms, deep learning, NLP, computer vision, and more. Perfect for data science interviews and exam preparation.

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📝Machine Learning MCQs(120 questions)

1

What is Machine Learning?

  • A

    A subset of AI that enables systems to learn from data

  • B

    A programming language for AI

  • C

    A database management system

  • D

    A type of hardware

Show Answer
A. A subset of AI that enables systems to learn from data
2

Who coined the term 'Machine Learning'?

  • A

    Arthur Samuel

  • B

    Alan Turing

  • C

    Geoffrey Hinton

  • D

    Andrew Ng

Show Answer
A. Arthur Samuel
3

What are the three main types of machine learning?

  • A

    Supervised, Unsupervised, Reinforcement

  • B

    Linear, Logistic, Neural

  • C

    Classification, Regression, Clustering

  • D

    Training, Testing, Validation

Show Answer
A. Supervised, Unsupervised, Reinforcement
4

What is the difference between AI and ML?

  • A

    AI is the broader concept, ML is a subset of AI

  • B

    ML is the broader concept, AI is a subset

  • C

    They are the same thing

  • D

    AI is older than ML

Show Answer
A. AI is the broader concept, ML is a subset of AI
5

What is the role of a loss function in ML?

  • A

    To measure how well the model performs

  • B

    To optimize the model's parameters

  • C

    To split the data

  • D

    To visualize data

Show Answer
A. To measure how well the model performs
6

What is overfitting in machine learning?

  • A

    Model performs well on training data but poorly on new data

  • B

    Model performs poorly on both training and new data

  • C

    Model performs equally well on all data

  • D

    Model fails to learn from training data

Show Answer
A. Model performs well on training data but poorly on new data
7

What is supervised learning?

  • A

    Learning from labeled data

  • B

    Learning from unlabeled data

  • C

    Learning through trial and error

  • D

    Learning without any data

Show Answer
A. Learning from labeled data
8

Which of the following is a classification algorithm?

  • A

    Logistic Regression

  • B

    Linear Regression

  • C

    K-Means

  • D

    PCA

Show Answer
A. Logistic Regression
9

What is the difference between classification and regression?

  • A

    Classification predicts discrete labels, regression predicts continuous values

  • B

    Regression predicts discrete labels, classification predicts continuous values

  • C

    Both predict continuous values

  • D

    Both predict discrete labels

Show Answer
A. Classification predicts discrete labels, regression predicts continuous values
10

What is the k-Nearest Neighbors (KNN) algorithm?

  • A

    A non-parametric algorithm that classifies based on nearest neighbors

  • B

    A parametric algorithm that uses probability

  • C

    A reinforcement learning algorithm

  • D

    A deep learning algorithm

Show Answer
A. A non-parametric algorithm that classifies based on nearest neighbors
11

What is the purpose of the train-test split?

  • A

    To evaluate model performance on unseen data

  • B

    To increase training data

  • C

    To reduce overfitting

  • D

    To normalize data

Show Answer
A. To evaluate model performance on unseen data
12

What is a confusion matrix?

  • A

    A table used to evaluate classification model performance

  • B

    A matrix for regression analysis

  • C

    A visualization tool for clustering

  • D

    A neural network architecture

Show Answer
A. A table used to evaluate classification model performance
13

What is unsupervised learning?

  • A

    Learning from unlabeled data

  • B

    Learning from labeled data

  • C

    Learning through trial and error

  • D

    Learning with human feedback

Show Answer
A. Learning from unlabeled data
14

Which of the following is a clustering algorithm?

  • A

    K-Means

  • B

    Linear Regression

  • C

    Support Vector Machine

  • D

    Random Forest

Show Answer
A. K-Means
15

What is dimensionality reduction?

  • A

    Reducing the number of features/variables

  • B

    Reducing the number of data points

  • C

    Reducing the number of classes

  • D

    Reducing the model complexity

Show Answer
A. Reducing the number of features/variables
16

What is the purpose of PCA (Principal Component Analysis)?

  • A

    To reduce dimensionality and identify important features

  • B

    To classify data

  • C

    To cluster data

  • D

    To predict continuous values

Show Answer
A. To reduce dimensionality and identify important features
17

What is the difference between K-Means and Hierarchical clustering?

  • A

    K-Means requires number of clusters, Hierarchical creates a hierarchy

  • B

    Hierarchical requires number of clusters, K-Means creates a hierarchy

  • C

    Both create hierarchies

  • D

    Both require number of clusters

Show Answer
A. K-Means requires number of clusters, Hierarchical creates a hierarchy
18

What is anomaly detection?

  • A

    Identifying rare or unusual data points

  • B

    Identifying common data points

  • C

    Predicting future data points

  • D

    Creating new data points

Show Answer
A. Identifying rare or unusual data points
19

What is linear regression?

  • A

    A method to model the relationship between variables using a linear equation

  • B

    A classification algorithm

  • C

    A clustering algorithm

  • D

    A deep learning model

Show Answer
A. A method to model the relationship between variables using a linear equation
20

What is the cost function in linear regression?

  • A

    Mean Squared Error (MSE)

  • B

    Cross-entropy loss

  • C

    Hinge loss

  • D

    Log loss

Show Answer
A. Mean Squared Error (MSE)
21

What is the purpose of gradient descent?

  • A

    To minimize the cost function by updating parameters

  • B

    To maximize the cost function

  • C

    To split the data

  • D

    To visualize the data

Show Answer
A. To minimize the cost function by updating parameters
22

What is the difference between simple and multiple linear regression?

  • A

    Simple uses one independent variable, multiple uses several

  • B

    Multiple uses one independent variable, simple uses several

  • C

    Both use one variable

  • D

    Both use multiple variables

Show Answer
A. Simple uses one independent variable, multiple uses several
23

What is R-squared (R²) in regression?

  • A

    A measure of how well the model explains the variance

  • B

    The error rate of the model

  • C

    The number of features

  • D

    The learning rate

Show Answer
A. A measure of how well the model explains the variance
24

What is regularization in regression?

  • A

    Techniques to prevent overfitting by adding a penalty term

  • B

    Techniques to increase overfitting

  • C

    Techniques to reduce data size

  • D

    Techniques to increase data size

Show Answer
A. Techniques to prevent overfitting by adding a penalty term
25

What is logistic regression?

  • A

    A classification algorithm that uses a sigmoid function

  • B

    A regression algorithm for continuous values

  • C

    A clustering algorithm

  • D

    A neural network

Show Answer
A. A classification algorithm that uses a sigmoid function
26

What is the purpose of the sigmoid function in logistic regression?

  • A

    To map output to probabilities between 0 and 1

  • B

    To map output to continuous values

  • C

    To cluster data

  • D

    To reduce dimensions

Show Answer
A. To map output to probabilities between 0 and 1
27

What is the difference between logistic and linear regression?

  • A

    Logistic is for classification, linear is for regression

  • B

    Linear is for classification, logistic is for regression

  • C

    Both are for classification

  • D

    Both are for regression

Show Answer
A. Logistic is for classification, linear is for regression
28

What is the support vector machine (SVM)?

  • A

    A classification algorithm that finds the optimal hyperplane

  • B

    A clustering algorithm

  • C

    A regression algorithm

  • D

    A neural network

Show Answer
A. A classification algorithm that finds the optimal hyperplane
29

What is the kernel trick in SVM?

  • A

    A method to transform data to higher dimensions without explicit computation

  • B

    A method to reduce dimensions

  • C

    A method to cluster data

  • D

    A method to normalize data

Show Answer
A. A method to transform data to higher dimensions without explicit computation
30

What is the difference between bagging and boosting?

  • A

    Bagging trains models in parallel, boosting trains sequentially

  • B

    Boosting trains models in parallel, bagging trains sequentially

  • C

    Both train in parallel

  • D

    Both train sequentially

Show Answer
A. Bagging trains models in parallel, boosting trains sequentially
31

What is a decision tree?

  • A

    A tree-like model that makes decisions based on feature values

  • B

    A neural network architecture

  • C

    A clustering algorithm

  • D

    A regression algorithm

Show Answer
A. A tree-like model that makes decisions based on feature values
32

What is entropy in decision trees?

  • A

    A measure of randomness or impurity

  • B

    A measure of accuracy

  • C

    A measure of precision

  • D

    A measure of recall

Show Answer
A. A measure of randomness or impurity
33

What is information gain?

  • A

    The reduction in entropy after splitting on a feature

  • B

    The increase in accuracy

  • C

    The reduction in training time

  • D

    The increase in data size

Show Answer
A. The reduction in entropy after splitting on a feature
34

What is the Gini impurity?

  • A

    A measure of how often a randomly chosen element would be incorrectly classified

  • B

    A measure of model accuracy

  • C

    A measure of model precision

  • D

    A measure of model recall

Show Answer
A. A measure of how often a randomly chosen element would be incorrectly classified
35

What is the difference between a decision tree and random forest?

  • A

    Random forest is an ensemble of multiple decision trees

  • B

    Decision tree is an ensemble of random forests

  • C

    Both are the same

  • D

    Decision tree is more accurate

Show Answer
A. Random forest is an ensemble of multiple decision trees
36

What is pruning in decision trees?

  • A

    Removing branches to reduce overfitting

  • B

    Adding branches to increase complexity

  • C

    Increasing tree depth

  • D

    Decreasing tree depth

Show Answer
A. Removing branches to reduce overfitting
37

What is the purpose of ensemble methods?

  • A

    To combine multiple models for better performance

  • B

    To use a single model

  • C

    To reduce data size

  • D

    To increase data size

Show Answer
A. To combine multiple models for better performance
38

What is the Random Forest algorithm?

  • A

    An ensemble of decision trees using bagging

  • B

    A single decision tree

  • C

    A neural network

  • D

    A clustering algorithm

Show Answer
A. An ensemble of decision trees using bagging
39

What is the difference between bagging and boosting?

  • A

    Bagging reduces variance, boosting reduces bias

  • B

    Boosting reduces variance, bagging reduces bias

  • C

    Both reduce variance

  • D

    Both reduce bias

Show Answer
A. Bagging reduces variance, boosting reduces bias
40

What is XGBoost?

  • A

    An optimized gradient boosting algorithm

  • B

    A random forest implementation

  • C

    A neural network library

  • D

    A clustering algorithm

Show Answer
A. An optimized gradient boosting algorithm
41

What is AdaBoost?

  • A

    Adaptive Boosting that gives more weight to misclassified samples

  • B

    A random forest algorithm

  • C

    A neural network

  • D

    A clustering algorithm

Show Answer
A. Adaptive Boosting that gives more weight to misclassified samples
42

What is stacking in ensemble learning?

  • A

    Combining multiple models using a meta-model

  • B

    Training models in sequence

  • C

    Training models in parallel

  • D

    Using a single model

Show Answer
A. Combining multiple models using a meta-model
43

What is accuracy in classification?

  • A

    The ratio of correct predictions to total predictions

  • B

    The ratio of false positives to true positives

  • C

    The ratio of true positives to false positives

  • D

    The ratio of false negatives to true negatives

Show Answer
A. The ratio of correct predictions to total predictions
44

What is precision in classification?

  • A

    The ratio of true positives to all positive predictions

  • B

    The ratio of true positives to all actual positives

  • C

    The ratio of correct predictions to all predictions

  • D

    The ratio of false positives to true positives

Show Answer
A. The ratio of true positives to all positive predictions
45

What is recall (sensitivity) in classification?

  • A

    The ratio of true positives to all actual positives

  • B

    The ratio of true positives to all positive predictions

  • C

    The ratio of correct predictions to all predictions

  • D

    The ratio of false positives to true positives

Show Answer
A. The ratio of true positives to all actual positives
46

What is the F1 score?

  • A

    The harmonic mean of precision and recall

  • B

    The arithmetic mean of precision and recall

  • C

    The geometric mean of precision and recall

  • D

    The sum of precision and recall

Show Answer
A. The harmonic mean of precision and recall
47

What is the ROC curve?

  • A

    A curve that plots true positive rate vs false positive rate

  • B

    A curve that plots precision vs recall

  • C

    A curve that plots accuracy vs error rate

  • D

    A curve that plots loss vs epochs

Show Answer
A. A curve that plots true positive rate vs false positive rate
48

What is cross-validation?

  • A

    A technique to evaluate model performance by splitting data into folds

  • B

    A technique to increase data size

  • C

    A technique to reduce features

  • D

    A technique to optimize hyperparameters

Show Answer
A. A technique to evaluate model performance by splitting data into folds
49

What is a neural network?

  • A

    A computational model inspired by the human brain

  • B

    A linear regression model

  • C

    A decision tree

  • D

    A clustering algorithm

Show Answer
A. A computational model inspired by the human brain
50

What is a perceptron?

  • A

    The simplest type of neural network with one layer

  • B

    A deep neural network

  • C

    A convolutional neural network

  • D

    A recurrent neural network

Show Answer
A. The simplest type of neural network with one layer
51

What is the role of activation functions in neural networks?

  • A

    To introduce non-linearity

  • B

    To introduce linearity

  • C

    To reduce dimensions

  • D

    To cluster data

Show Answer
A. To introduce non-linearity
52

What is backpropagation?

  • A

    An algorithm to update weights by propagating error backwards

  • B

    An algorithm to propagate input forward

  • C

    An algorithm to reduce dimensions

  • D

    An algorithm to cluster data

Show Answer
A. An algorithm to update weights by propagating error backwards
53

What is the difference between a shallow and deep neural network?

  • A

    Shallow has few layers, deep has many layers

  • B

    Deep has few layers, shallow has many layers

  • C

    Both have the same number of layers

  • D

    Shallow is more accurate

Show Answer
A. Shallow has few layers, deep has many layers
54

What is the purpose of the learning rate in training neural networks?

  • A

    To control the step size in gradient descent

  • B

    To control the number of epochs

  • C

    To control the batch size

  • D

    To control the number of layers

Show Answer
A. To control the step size in gradient descent
55

What is deep learning?

  • A

    A subset of ML using deep neural networks

  • B

    A subset of AI without neural networks

  • C

    A type of clustering

  • D

    A type of regression

Show Answer
A. A subset of ML using deep neural networks
56

What is a convolutional neural network (CNN)?

  • A

    A neural network designed for image and spatial data

  • B

    A neural network for sequential data

  • C

    A neural network for text data

  • D

    A neural network for tabular data

Show Answer
A. A neural network designed for image and spatial data
57

What is a recurrent neural network (RNN)?

  • A

    A neural network designed for sequential data

  • B

    A neural network for image data

  • C

    A neural network for tabular data

  • D

    A neural network with no connections

Show Answer
A. A neural network designed for sequential data
58

What is the vanishing gradient problem?

  • A

    Gradients become too small for effective learning in deep networks

  • B

    Gradients become too large

  • C

    Gradients become zero

  • D

    Gradients become infinite

Show Answer
A. Gradients become too small for effective learning in deep networks
59

What is the purpose of dropout in neural networks?

  • A

    To prevent overfitting by randomly dropping neurons

  • B

    To increase model complexity

  • C

    To reduce training time

  • D

    To increase accuracy

Show Answer
A. To prevent overfitting by randomly dropping neurons
60

What is transfer learning?

  • A

    Using knowledge from one task to improve performance on another

  • B

    Learning from scratch

  • C

    Learning without data

  • D

    Learning with no labels

Show Answer
A. Using knowledge from one task to improve performance on another
61

What is the difference between mean and median?

  • A

    Mean is sensitive to outliers, median is robust

  • B

    Median is sensitive to outliers, mean is robust

  • C

    Both are sensitive to outliers

  • D

    Both are robust to outliers

Show Answer
A. Mean is sensitive to outliers, median is robust
62

What is standard deviation?

  • A

    A measure of the spread of data around the mean

  • B

    A measure of central tendency

  • C

    A measure of correlation

  • D

    A measure of probability

Show Answer
A. A measure of the spread of data around the mean
63

What is the difference between correlation and causation?

  • A

    Correlation doesn't imply causation

  • B

    Correlation implies causation

  • C

    They are the same

  • D

    Causation doesn't imply correlation

Show Answer
A. Correlation doesn't imply causation
64

What is a p-value in statistics?

  • A

    The probability of observing results as extreme as the observed, assuming null hypothesis is true

  • B

    The probability that the null hypothesis is true

  • C

    The probability of a Type I error

  • D

    The probability of a Type II error

Show Answer
A. The probability of observing results as extreme as the observed, assuming null hypothesis is true
65

What is a normal distribution?

  • A

    A symmetric bell-shaped distribution

  • B

    A skewed distribution

  • C

    A uniform distribution

  • D

    A bimodal distribution

Show Answer
A. A symmetric bell-shaped distribution
66

What is Bayes theorem used for in ML?

  • A

    To calculate conditional probabilities for classification

  • B

    To calculate means and variances

  • C

    To calculate correlations

  • D

    To calculate standard deviations

Show Answer
A. To calculate conditional probabilities for classification
67

What is feature scaling?

  • A

    Normalizing features to a common range

  • B

    Adding new features

  • C

    Removing features

  • D

    Creating features

Show Answer
A. Normalizing features to a common range
68

What is the difference between normalization and standardization?

  • A

    Normalization scales to [0,1], standardization has mean 0, std 1

  • B

    Standardization scales to [0,1], normalization has mean 0, std 1

  • C

    Both are the same

  • D

    Neither is used

Show Answer
A. Normalization scales to [0,1], standardization has mean 0, std 1
69

What is one-hot encoding?

  • A

    Converting categorical variables to binary vectors

  • B

    Converting continuous variables to categorical

  • C

    Converting text to numbers

  • D

    Converting numbers to text

Show Answer
A. Converting categorical variables to binary vectors
70

What is feature selection?

  • A

    Choosing the most relevant features for the model

  • B

    Creating new features

  • C

    Scaling features

  • D

    Encoding features

Show Answer
A. Choosing the most relevant features for the model
71

What is the purpose of feature engineering?

  • A

    To improve model performance by creating better features

  • B

    To reduce data size

  • C

    To increase data size

  • D

    To remove all features

Show Answer
A. To improve model performance by creating better features
72

What is the curse of dimensionality?

  • A

    The problem of high-dimensional data leading to sparsity and overfitting

  • B

    The problem of too little data

  • C

    The problem of too many samples

  • D

    The problem of missing values

Show Answer
A. The problem of high-dimensional data leading to sparsity and overfitting
73

What is Natural Language Processing (NLP)?

  • A

    The interaction between computers and human language

  • B

    Processing numerical data

  • C

    Processing images

  • D

    Processing audio

Show Answer
A. The interaction between computers and human language
74

What is tokenization in NLP?

  • A

    Splitting text into smaller units like words or sentences

  • B

    Converting text to numbers

  • C

    Removing stop words

  • D

    Lemmatizing words

Show Answer
A. Splitting text into smaller units like words or sentences
75

What is the difference between stemming and lemmatization?

  • A

    Stemming is rule-based, lemmatization uses vocabulary and morphology

  • B

    Lemmatization is rule-based, stemming uses vocabulary

  • C

    Both are the same

  • D

    Neither is used

Show Answer
A. Stemming is rule-based, lemmatization uses vocabulary and morphology
76

What is a word embedding?

  • A

    A dense vector representation of words

  • B

    A one-hot encoding of words

  • C

    A bag-of-words representation

  • D

    A TF-IDF representation

Show Answer
A. A dense vector representation of words
77

What is the purpose of stop word removal in NLP?

  • A

    To remove common words that don't add significant meaning

  • B

    To remove all words

  • C

    To keep only stop words

  • D

    To remove all content words

Show Answer
A. To remove common words that don't add significant meaning
78

What is the Transformer architecture?

  • A

    A neural network architecture using attention mechanisms

  • B

    A traditional RNN architecture

  • C

    A CNN architecture

  • D

    A decision tree architecture

Show Answer
A. A neural network architecture using attention mechanisms
79

What is computer vision?

  • A

    The field of AI that deals with visual data

  • B

    The field of AI that deals with text

  • C

    The field of AI that deals with audio

  • D

    The field of AI that deals with tabular data

Show Answer
A. The field of AI that deals with visual data
80

What is image classification?

  • A

    Assigning a class label to an image

  • B

    Detecting objects in an image

  • C

    Segmenting an image

  • D

    Generating an image

Show Answer
A. Assigning a class label to an image
81

What is object detection?

  • A

    Identifying and locating objects in an image

  • B

    Classifying the entire image

  • C

    Segmenting the image

  • D

    Generating the image

Show Answer
A. Identifying and locating objects in an image
82

What is image segmentation?

  • A

    Dividing an image into segments based on pixel groups

  • B

    Classifying the entire image

  • C

    Detecting objects in the image

  • D

    Generating the image

Show Answer
A. Dividing an image into segments based on pixel groups
83

What is the purpose of max pooling in CNNs?

  • A

    To reduce spatial dimensions while preserving important features

  • B

    To increase spatial dimensions

  • C

    To add non-linearity

  • D

    To normalize features

Show Answer
A. To reduce spatial dimensions while preserving important features
84

What is the difference between object detection and object segmentation?

  • A

    Detection gives bounding boxes, segmentation gives pixel-level masks

  • B

    Segmentation gives bounding boxes, detection gives pixel-level masks

  • C

    Both give bounding boxes

  • D

    Both give pixel-level masks

Show Answer
A. Detection gives bounding boxes, segmentation gives pixel-level masks
85

What is reinforcement learning?

  • A

    Learning through interaction with an environment to maximize rewards

  • B

    Learning from labeled data

  • C

    Learning from unlabeled data

  • D

    Learning without any data

Show Answer
A. Learning through interaction with an environment to maximize rewards
86

What is an agent in reinforcement learning?

  • A

    The learner that interacts with the environment

  • B

    The environment itself

  • C

    The reward function

  • D

    The policy

Show Answer
A. The learner that interacts with the environment
87

What is a policy in reinforcement learning?

  • A

    A strategy that the agent follows to decide actions

  • B

    The reward function

  • C

    The environment

  • D

    The state space

Show Answer
A. A strategy that the agent follows to decide actions
88

What is the exploration-exploitation tradeoff?

  • A

    Balancing between trying new actions and using known good actions

  • B

    Balancing between training and testing

  • C

    Balancing between supervised and unsupervised learning

  • D

    Balancing between classification and regression

Show Answer
A. Balancing between trying new actions and using known good actions
89

What is Q-learning?

  • A

    A value-based reinforcement learning algorithm

  • B

    A policy-based reinforcement learning algorithm

  • C

    A supervised learning algorithm

  • D

    An unsupervised learning algorithm

Show Answer
A. A value-based reinforcement learning algorithm
90

What is the reward signal in reinforcement learning?

  • A

    Feedback from the environment indicating the quality of an action

  • B

    The prediction error

  • C

    The classification accuracy

  • D

    The clustering quality

Show Answer
A. Feedback from the environment indicating the quality of an action
91

What is MLOps?

  • A

    The practice of managing ML model lifecycle in production

  • B

    The practice of training ML models

  • C

    The practice of data engineering

  • D

    The practice of model evaluation

Show Answer
A. The practice of managing ML model lifecycle in production
92

What is model versioning?

  • A

    Tracking different versions of ML models

  • B

    Tracking data versions

  • C

    Tracking code versions

  • D

    Tracking hardware versions

Show Answer
A. Tracking different versions of ML models
93

What is model drift?

  • A

    The degradation of model performance over time

  • B

    The improvement of model performance over time

  • C

    The change in model architecture

  • D

    The change in model parameters

Show Answer
A. The degradation of model performance over time
94

What is the purpose of A/B testing in ML?

  • A

    To compare two models and choose the better one

  • B

    To test model accuracy

  • C

    To test model precision

  • D

    To test model recall

Show Answer
A. To compare two models and choose the better one
95

What is model monitoring in production?

  • A

    Continuously tracking model performance and health

  • B

    Training the model

  • C

    Deploying the model

  • D

    Testing the model

Show Answer
A. Continuously tracking model performance and health
96

What is the difference between model training and inference?

  • A

    Training learns patterns, inference applies learned patterns to new data

  • B

    Inference learns patterns, training applies learned patterns

  • C

    Both learn patterns

  • D

    Both apply learned patterns

Show Answer
A. Training learns patterns, inference applies learned patterns to new data
97

What is clustering?

  • A

    Grouping similar data points together

  • B

    Classifying data points into predefined categories

  • C

    Predicting continuous values

  • D

    Reducing data dimensions

Show Answer
A. Grouping similar data points together
98

What is the Elbow method in K-Means clustering?

  • A

    A method to find the optimal number of clusters

  • B

    A method to initialize centroids

  • C

    A method to evaluate cluster quality

  • D

    A method to visualize clusters

Show Answer
A. A method to find the optimal number of clusters
99

What is the Silhouette score?

  • A

    A measure of how similar a point is to its own cluster compared to others

  • B

    A measure of cluster size

  • C

    A measure of cluster density

  • D

    A measure of cluster distance

Show Answer
A. A measure of how similar a point is to its own cluster compared to others
100

What is the difference between K-Means and DBSCAN?

  • A

    K-Means is centroid-based, DBSCAN is density-based

  • B

    DBSCAN is centroid-based, K-Means is density-based

  • C

    Both are centroid-based

  • D

    Both are density-based

Show Answer
A. K-Means is centroid-based, DBSCAN is density-based
101

What is hierarchical clustering?

  • A

    Creating a hierarchy of clusters in a tree-like structure

  • B

    Creating clusters of equal size

  • C

    Creating clusters based on density

  • D

    Creating clusters based on centroids

Show Answer
A. Creating a hierarchy of clusters in a tree-like structure
102

What is the purpose of the dendrogram in hierarchical clustering?

  • A

    To visualize the hierarchy of clusters

  • B

    To measure cluster quality

  • C

    To initialize centroids

  • D

    To assign cluster labels

Show Answer
A. To visualize the hierarchy of clusters
103

What is the difference between training and testing data?

  • A

    Training data is used to learn, testing data is used to evaluate

  • B

    Testing data is used to learn, training data is used to evaluate

  • C

    Both are used for learning

  • D

    Both are used for evaluation

Show Answer
A. Training data is used to learn, testing data is used to evaluate
104

What is a support vector?

  • A

    The data points closest to the decision boundary in SVM

  • B

    The data points farthest from the decision boundary

  • C

    The centroids of clusters

  • D

    The means of distributions

Show Answer
A. The data points closest to the decision boundary in SVM
105

What is the purpose of the intercept in linear regression?

  • A

    To allow the model to fit data that doesn't pass through the origin

  • B

    To increase model complexity

  • C

    To reduce overfitting

  • D

    To increase accuracy

Show Answer
A. To allow the model to fit data that doesn't pass through the origin
106

What is the difference between binary and multi-class classification?

  • A

    Binary has two classes, multi-class has more than two

  • B

    Multi-class has two classes, binary has more than two

  • C

    Both have two classes

  • D

    Both have more than two classes

Show Answer
A. Binary has two classes, multi-class has more than two
107

What is the difference between ID3 and C4.5 algorithms?

  • A

    ID3 uses information gain, C4.5 uses gain ratio

  • B

    C4.5 uses information gain, ID3 uses gain ratio

  • C

    Both use information gain

  • D

    Both use gain ratio

Show Answer
A. ID3 uses information gain, C4.5 uses gain ratio
108

What is the purpose of the 'weak learner' in boosting?

  • A

    To perform slightly better than random guessing

  • B

    To perform perfectly

  • C

    To perform poorly

  • D

    To perform randomly

Show Answer
A. To perform slightly better than random guessing
109

What is the difference between accuracy and balanced accuracy?

  • A

    Balanced accuracy handles class imbalance better

  • B

    Accuracy handles class imbalance better

  • C

    Both are the same

  • D

    Neither handles class imbalance

Show Answer
A. Balanced accuracy handles class imbalance better
110

What is the purpose of batch normalization?

  • A

    To normalize inputs of each layer to improve training

  • B

    To reduce model complexity

  • C

    To increase model complexity

  • D

    To reduce training time

Show Answer
A. To normalize inputs of each layer to improve training
111

What is the difference between a CNN and an RNN?

  • A

    CNN is for spatial data, RNN is for sequential data

  • B

    RNN is for spatial data, CNN is for sequential data

  • C

    Both are for spatial data

  • D

    Both are for sequential data

Show Answer
A. CNN is for spatial data, RNN is for sequential data
112

What is the difference between covariance and correlation?

  • A

    Correlation is a normalized version of covariance

  • B

    Covariance is a normalized version of correlation

  • C

    Both are the same

  • D

    Neither is normalized

Show Answer
A. Correlation is a normalized version of covariance
113

What is the purpose of polynomial features?

  • A

    To create non-linear features from linear ones

  • B

    To reduce features

  • C

    To encode categorical features

  • D

    To scale features

Show Answer
A. To create non-linear features from linear ones
114

What is the purpose of TF-IDF?

  • A

    To weight words based on importance in a document

  • B

    To convert text to word embeddings

  • C

    To remove stop words

  • D

    To perform tokenization

Show Answer
A. To weight words based on importance in a document
115

What is the purpose of data augmentation in computer vision?

  • A

    To increase the diversity of training data

  • B

    To reduce the size of training data

  • C

    To remove noise from images

  • D

    To compress images

Show Answer
A. To increase the diversity of training data
116

What is the difference between on-policy and off-policy learning?

  • A

    On-policy uses current policy, off-policy can use different policies

  • B

    Off-policy uses current policy, on-policy can use different policies

  • C

    Both use current policy

  • D

    Both use different policies

Show Answer
A. On-policy uses current policy, off-policy can use different policies
117

What is the purpose of CI/CD in MLOps?

  • A

    To automate model training and deployment

  • B

    To manually train models

  • C

    To manually deploy models

  • D

    To evaluate models

Show Answer
A. To automate model training and deployment
118

What is the difference between soft and hard clustering?

  • A

    Hard assigns each point to one cluster, soft assigns probabilities

  • B

    Soft assigns each point to one cluster, hard assigns probabilities

  • C

    Both assign to one cluster

  • D

    Both assign probabilities

Show Answer
A. Hard assigns each point to one cluster, soft assigns probabilities
119

What is the difference between model parameters and hyperparameters?

  • A

    Parameters are learned, hyperparameters are set before training

  • B

    Hyperparameters are learned, parameters are set before training

  • C

    Both are learned

  • D

    Both are set before training

Show Answer
A. Parameters are learned, hyperparameters are set before training
120

What is the purpose of the bias term in machine learning models?

  • A

    To allow the model to fit data that doesn't pass through the origin

  • B

    To increase model complexity

  • C

    To reduce overfitting

  • D

    To increase accuracy

Show Answer
A. To allow the model to fit data that doesn't pass through the origin

Frequently Asked Questions

What is Machine Learning?
Machine Learning is a subset of Artificial Intelligence that enables systems to learn and improve from experience without being explicitly programmed. It involves algorithms that can identify patterns and make predictions from data.
What are the main types of machine learning?
The three main types are: Supervised Learning (learning from labeled data), Unsupervised Learning (finding patterns in unlabeled data), and Reinforcement Learning (learning through trial and error with rewards).
What is the difference between AI and ML?
AI is the broader concept of machines being able to carry out tasks in a way that we would consider 'smart'. ML is a subset of AI that uses data and algorithms to mimic how humans learn, gradually improving its accuracy.
How can I start learning machine learning?
Start with basic statistics and Python programming, then learn core ML algorithms (linear regression, decision trees, SVM), practice with libraries like scikit-learn, and finally explore deep learning. Kaggle is a great platform for practice.
What are the prerequisites for ML?
Key prerequisites include: Python programming, basic statistics and probability, linear algebra, and calculus. Knowledge of data structures and algorithms is also helpful.
Is machine learning still relevant in 2026?
Yes, ML is more relevant than ever with applications in healthcare, finance, autonomous vehicles, natural language processing, and recommendation systems. The field continues to grow with new advancements in deep learning and LLMs.