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Generative AI LLMs Questions 36–40 (page: 9)

Updated On: 10-Feb-2026

Which of the following prompt engineering techniques is most effective for improving an LLM's performance on multi-step reasoning tasks?

  1. Retrieval-augmented generation without context
  2. Few-shot prompting with unrelated examples.
  3. Zero-shot prompting with detailed task descriptions.
  4. Chain-of-thought prompting with explicit intermediate steps.

Answer(s): D

Explanation:

Chain-of-thought (CoT) prompting is a highly effective technique for improving large language model (LLM) performance on multi-step reasoning tasks. By including explicit intermediate steps in the prompt, CoT guides the model to break down complex problems into manageable parts, improving reasoning accuracy. NVIDIA's NeMo documentation on prompt engineering highlights CoT as a powerful method for tasks like mathematical reasoning or logical problem-solving, as it leverages the model's ability to follow structured reasoning paths. Option A is incorrect, as retrieval-augmented generation (RAG) without context is less effective for reasoning tasks. Option B is wrong, as unrelated examples in few-shot prompting do not aid reasoning. Option C (zero-shot prompting) is less effective than CoT for complex reasoning.


Reference:

NVIDIA NeMo Documentation: https://docs.nvidia.com/deeplearning/nemo/user- guide/docs/en/stable/nlp/intro.html
Wei, J., et al. (2022). "Chain-of-Thought Prompting Elicits Reasoning in Large Language Models."



What is the purpose of few-shot learning in prompt engineering?

  1. To give a model some examples
  2. To train a model from scratch
  3. To optimize hyperparameters
  4. To fine-tune a model on a massive dataset

Answer(s): A

Explanation:

Few-shot learning in prompt engineering involves providing a small number of examples (demonstrations) within the prompt to guide a large language model (LLM) to perform a specific task without modifying its weights. NVIDIA's NeMo documentation on prompt-based learning explains that few-shot prompting leverages the model's pre-trained knowledge by showing it a few input- output pairs, enabling it to generalize to new tasks. For example, providing two examples of sentiment classification in a prompt helps the model understand the task. Option B is incorrect, as few-shot learning does not involve training from scratch. Option C is wrong, as hyperparameter optimization is a separate process. Option D is false, as few-shot learning avoids large-scale fine- tuning.


Reference:

NVIDIA NeMo Documentation: https://docs.nvidia.com/deeplearning/nemo/user- guide/docs/en/stable/nlp/intro.html
Brown, T., et al. (2020). "Language Models are Few-Shot Learners."



When fine-tuning an LLM for a specific application, why is it essential to perform exploratory data analysis (EDA) on the new training dataset?

  1. To uncover patterns and anomalies in the dataset
  2. To select the appropriate learning rate for the model
  3. To assess the computing resources required for fine-tuning
  4. To determine the optimum number of layers in the neural network

Answer(s): A

Explanation:

Exploratory Data Analysis (EDA) is a critical step in fine-tuning large language models (LLMs) to understand the characteristics of the new training dataset. NVIDIA's NeMo documentation on data preprocessing for NLP tasks emphasizes that EDA helps uncover patterns (e.g., class distributions, word frequencies) and anomalies (e.g., outliers, missing values) that can affect model performance. For example, EDA might reveal imbalanced classes or noisy data, prompting preprocessing steps like data cleaning or augmentation. Option B is incorrect, as learning rate selection is part of model training, not EDA. Option C is unrelated, as EDA does not assess computational resources. Option D is false, as the number of layers is a model architecture decision, not derived from EDA.


Reference:

NVIDIA NeMo Documentation: https://docs.nvidia.com/deeplearning/nemo/user- guide/docs/en/stable/nlp/intro.html



In the Transformer architecture, which of the following statements about the Q (query), K (key), and V (value) matrices is correct?

  1. Q, K, and V are randomly initialized weight matrices used for positional encoding.
  2. K is responsible for computing the attention scores between the query and key vectors.
  3. Q represents the query vector used to retrieve relevant information from the input sequence.
  4. V is used to calculate the positional embeddings for each token in the input sequence.

Answer(s): C

Explanation:

In the transformer architecture, the Q (query), K (key), and V (value) matrices are used in the self- attention mechanism to compute relationships between tokens in a sequence. According to "Attention is All You Need" (Vaswani et al., 2017) and NVIDIA's NeMo documentation, the query vector (Q) represents the token seeking relevant information, the key vector (K) is used to compute compatibility with other tokens, and the value vector (V) provides the information to be retrieved. The attention score is calculated as a scaled dot-product of Q and K, and the output is a weighted sum of V. Option C is correct, as Q retrieves relevant information. Option A is incorrect, as Q, K, and V are not used for positional encoding. Option B is wrong, as attention scores are computed using both Q and K, not K alone. Option D is false, as positional embeddings are separate from V.


Reference:

Vaswani, A., et al. (2017). "Attention is All You Need." NVIDIA NeMo Documentation: https://docs.nvidia.com/deeplearning/nemo/user- guide/docs/en/stable/nlp/intro.html



In the context of transformer-based large language models, how does the use of layer normalization mitigate the challenges associated with training deep neural networks?

  1. It reduces the computational complexity by normalizing the input embeddings.
  2. It stabilizes training by normalizing the inputs to each layer, reducing internal covariate shift.
  3. It increases the model's capacity by adding additional parameters to each layer.
  4. It replaces the attention mechanism to improve sequence processing efficiency.

Answer(s): B

Explanation:

Layer normalization is a technique used in transformer-based large language models (LLMs) to stabilize and accelerate training by normalizing the inputs to each layer. According to the original transformer paper ("Attention is All You Need," Vaswani et al., 2017) and NVIDIA's NeMo documentation, layer normalization reduces internal covariate shift by ensuring that the mean and variance of activations remain consistent across layers, mitigating issues like vanishing or exploding gradients in deep networks. This is particularly crucial in transformers, which have many layers and process long sequences, making them prone to training instability. By normalizing the activations (typically after the attention and feed-forward sub-layers), layer normalization improves gradient flow and convergence. Option A is incorrect, as layer normalization does not reduce computational complexity but adds a small overhead. Option C is false, as it does not add significant parameters. Option D is wrong, as layer normalization complements, not replaces, the attention mechanism.


Reference:

Vaswani, A., et al. (2017). "Attention is All You Need." NVIDIA NeMo Documentation: https://docs.nvidia.com/deeplearning/nemo/user- guide/docs/en/stable/nlp/intro.html



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