Question 1
Deterministic neural network
Probabilistic neural network
The IIT Madras BS Mathematical Foundations of Generative AI (Mathematical Foundations of Generative AI) Quiz 2 paper sat on 16 Aug 2026, in the May 2026 term: 17 questions for 48 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.
Deterministic neural network
Probabilistic neural network
Correct answer
Probabilistic neural network
A Variational Autoencoder (VAE) has been trained on a dataset. Which of the following procedures correctly generates a new data sample from the trained model?
Optimize the KL divergence term during inference until it becomes zero, and then decode the resulting latent representation.
Correct answer
To make the critic network deeper.
Correct answer
None of these
Correct answer
Correct answer
Correct answers
Choosing a very small value of β increases the influence of the KL divergence term, forcing the approximate posterior to collapse towards the prior.
Choosing a very large value of β places greater emphasis on matching the approximate posterior to the prior, which may degrade reconstruction quality.
Correct answers
Choosing a very large value of β places greater emphasis on matching the approximate posterior to the prior, which may degrade reconstruction quality.
A latent variable model defines
Correct answers
Which of the following statements correctly contrast DDPM sampling with a standard GAN/VAE?
A trained DDPM directly generate a data sample in a single network evaluation.
During sampling, a DDPM starts from a real training sample and removes the added noise in a single denoising step.
Correct answers
Which of the following statements about the generator and discriminator in a standard GAN are correct?
The generator never sees real data directly; it learns only through the gradient signal that flows back from the discriminator.
The discriminator is a binary classifier trained on a mix of real samples (label 1) and generated samples (label 0).
The discriminator's role is to distinguish real samples from generated ones.
The discriminator generates new data samples from the latent space.
Correct answers
The generator never sees real data directly; it learns only through the gradient signal that flows back from the discriminator.
The discriminator is a binary classifier trained on a mix of real samples (label 1) and generated samples (label 0).
The discriminator's role is to distinguish real samples from generated ones.
Which among the following is true for a denoising diffusion probabilistic model (DDPM)?
The forward process in DDPM gradually adds noise to the input.
The forward process in DDPM learns to generate data by denoising.
In the reverse process of DDPM, we stack the VAE decoders.
In the reverse process of DDPM, we stack the VAE encoders.
Correct answers
The forward process in DDPM gradually adds noise to the input.
In the reverse process of DDPM, we stack the VAE decoders.
Correct answer: 0
Correct answer: 2
Based on the above data, answer the given subquestions.
Correct answer: 0.12 (accepted within ±0.02)
Based on the above data, answer the given subquestions.
Correct answer: 0.79 (accepted within ±0.02)
Correct answer: 0.9 (accepted within ±0.02)
Correct answer: 0.6 (accepted within ±0.02)