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Module-level Graded Quiz: Tensor and Dataset :Introduction to Neural Networks and PyTorch (IBM AI Engineering Professional Certificate) Answers 2025

1. Question 1

Result of:

a = torch.tensor([1,2,3])
a.dtype
  • torch.int64

  • ❌ torch.float32

  • ❌ LongTensor

  • ❌ Float

Explanation:
PyTorch defaults integer tensors to int64 unless specified otherwise.


2. Question 2

Tensor type for unsigned integers used in 8-bit images:

  • Byte

  • ❌ Integer

  • ❌ Float

  • ❌ Double

Explanation:
8-bit images → values 0–255 → PyTorch uses torch.uint8 (Byte).


3. Question 3

What is a 2D tensor?

  • A matrix: rows = samples, columns = features

  • ❌ Scalar

  • ❌ 1D array

  • ❌ Single color channel

Explanation:
A 2D tensor is just a matrix.


4. Question 4

Method to get number of dimensions (rank):

  • ❌ shape()

  • ❌ numel()

  • ❌ size()

  • ndimension()

Explanation:
tensor.ndimension() returns the rank.


5. Question 5

Indexing second row, third column:

  • tensor[1, 2]

  • ❌ tensor[1][2]

  • ❌ tensor[2][1]

  • ❌ tensor[2, 1]

Explanation:
Indexing is zero-based → row 1, column 2.


6. Question 6

Given:

a = torch.tensor([[0,1,1],[1,0,1]])

a.size() and a.ndimension():

  • (2, 3), 2

  • ❌ (3,2), 3

  • ❌ (2,3), 3

  • ❌ (3,2), 2

Explanation:
2 rows × 3 columns → rank 2.


7. Question 7

Method to override to access items in dataset:

  • iter

  • init

  • getitem

  • len

Explanation:
__getitem__ retrieves items by index.


8. Question 8

How to apply a transform to a dataset:

  • Pass transform to the dataset constructor

  • ❌ Call transform() on dataset

  • ❌ apply_transform()

  • ❌ Manually transform each sample

Explanation:
Transforms are injected into the dataset class.


9. Question 9

Technique for applying multiple transforms:

  • Compose

  • ❌ Single transform

  • ❌ Splitting data

  • ❌ Convert to tensors

Explanation:
transforms.Compose([...]) chains operations.


10. Question 10

Purpose of Image.open():

  • ❌ Get image path

  • Read and load image into a PIL image format

  • ❌ Display image

  • ❌ Load directly into tensor

Explanation:
Image.open() loads an image into a PIL object.


🧾 Summary Table

Q# Correct Answer
1 torch.int64
2 Byte
3 Matrix (rows=samples, columns=features)
4 ndimension()
5 tensor[1, 2]
6 (2, 3), 2
7 getitem
8 Pass transform in constructor
9 Compose
10 Load image via Image.open()