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September 2023 term · Machine Learning Foundations · BSCS2004

MLF Quiz 2: 3 December 2023 (September 2023 term)

The IIT Madras BS Machine Learning Foundations (MLF) Quiz 2 paper sat on 3 Dec 2023, in the September 2023 term: 14 questions for 40 marks in 120 minutes. Every question is below with its answer. Take it as a timed mock test to be marked, or read it through first.

Questions
14
Marks
40
Duration
120 min
MCQ
8
MSQ
3
Numerical
3

Updated

Official paper: IIT M DIPLOMA AN2 EXAM QDD2 03 Dec 2023 · No negative marking.

Question 1

+3 marksOne correct option

Let U andV be two unitary matrices. Consider the following statements:
Statement 1: U + V is unitary.
Statement 2: UV is unitary.
Select the correct options from the following:

  1. A

    Only statement 2 is correct.

  2. B

    Both statement 1 and statement 2 are incorrect.

  3. C

    Both statement 1 and statement 2 are correct.

  4. D

    Only statement 1 is correct.

Show answer

Correct answer

  • A

    Only statement 2 is correct.

Question 2

+3 marksOne correct option

Consider a function f(x, y) = x² + y² − 4x − 2y + 5. Using gradient descent algorithm, with an initial guess of (3, 2) and learning rate of 0.1, what will be the value of (x, y) after one iteration?

  1. A

    x = 3.2, y = 2.2

  2. B

    x = 3, y = 2

  3. C

    x = 1.8,y = 0.8

  4. D

    x = 2.8, y = 1.8

Show answer

Correct answer

  • D

    x = 2.8, y = 1.8

Question 3

+3 marksOne correct option
  1. A

    x = 40, y = 20

  2. B

    x = 20, y = 40

  3. C

    x = 30, y = 30

  4. D

    x = 0, y = 60

  5. E

    None of these

Show answer

Correct answer

  • A

    x = 40, y = 20

Question 4

+4 marksOne correct option
  1. A
  2. B
  3. C
  4. D
Show answer

Correct answer

  • C

Question 5

+3 marksOne or more correct options

Select all that apply.

  1. A

    A is Hermitian matrix.

  2. B

    A is not Hermitian matrix.

  3. C

    A is unitarily diagonalizable.

  4. D

    A is not unitarily diagonalizable.

Show answer

Correct answers

  • B

    A is not Hermitian matrix.

  • C

    A is unitarily diagonalizable.

Question 6

+3 marksNumerical answer

For an n×nn \times n invertible matrix AA, the ratio σ1σn\dfrac{\sigma_1}{\sigma_n} gives the condition number of AA, where σ1\sigma_1 and σn\sigma_n represent the largest and the smallest singular values of AA, respectively. What will be the condition number σ1σ3\dfrac{\sigma_1}{\sigma_3} for the given matrix AA? Enter the answer correct to two decimal places.

Show answer

Correct answer: 2.23 (accepted within ±0.03)

Question 7

+2 marksOne correct option

Is the matrix A positive definite?

  1. A

    Yes

  2. B

    No

Show answer

Correct answer

  • A

    Yes

Question 8

+2 marksNumerical answer

What is the rank of A?

Show answer

Correct answer: 2

Question 9

+3 marksOne or more correct options

Which of the following options are true?

Select all that apply.

  1. A
  2. B
  3. C
  4. D
Show answer

Correct answers

  • A
  • D

Question 10

+2 marksOne or more correct options

Which among the following statements are true about principal component analysis (PCA)?

Select all that apply.

  1. A

    PCA is a supervised learning algorithm.

  2. B

    Principal components are the eigenvectors of the sample covariance matrix.

  3. C

    Principal components are eigenvectors of the centered data matrix.

  4. D

    If p1 and p2 are the principal component vectors, then p1 is orthogonal to p2.

Show answer

Correct answers

  • B

    Principal components are the eigenvectors of the sample covariance matrix.

  • D

    If p1 and p2 are the principal component vectors, then p1 is orthogonal to p2.

Question 11

+3 marksOne correct option

Compute the sample covariance matrix C for the given dataset.

  1. A
  2. B
  3. C
  4. D
Show answer

Correct answer

  • B

Question 12

+3 marksOne correct option

Which is the principal direction that is chosen for performing PCA?

  1. A
  2. B
  3. C
  4. D
Show answer

Correct answer

  • B

Question 13

+3 marksOne correct option
  1. A
  2. B
  3. C
  4. D
Show answer

Correct answer

  • D

Question 14

+3 marksNumerical answer
Show answer

Correct answer: 2