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NCA-GENL — NVIDIA Generative AI & LLMs Associate

NVIDIA Generative AI & LLMs Associate (NCA-GENL) — 2-Day Exam Prep

Exam: 50–60 questions | 60 minutes | Multiple choice Goal: Pass in 2 days with focused, high-yield study sprints.


Strategy Overview

Day Focus Areas Weight
Day 1 ML & Neural Network Foundations + Transformer / NLP Architecture 50% of exam
Day 2 NVIDIA Deployment Stack + Trustworthy AI 50% of exam

Study method: Read → Mnemonic → Active Recall (practice questions after each section).


DAY 1 — Foundations & Transformers


Section 1: Machine Learning & Neural Network Foundations (30%)

1.1 Types of Machine Learning

Type Description Example
Supervised Labeled data → learns mapping Spam detection
Unsupervised No labels → finds patterns Customer clustering
Semi-supervised Small labeled + large unlabeled Medical imaging
Self-supervised Creates own labels from data GPT pre-training (next-token prediction)
Reinforcement Agent → action → reward signal RLHF for LLMs

Mnemonic — "SUSS-R" Supervised, Unsupervised, Semi-supervised, Self-supervised, Reinforcement "SUSS out the Right learning type"

1.2 Neural Network Building Blocks

Component Purpose
Neuron Weighted sum + bias → activation function
Activation Functions Introduce non-linearity (ReLU, Sigmoid, Tanh, Softmax)
Loss Function Measures how wrong the model is (Cross-Entropy, MSE)
Optimizer Updates weights to minimize loss (SGD, Adam)
Backpropagation Chain rule to compute gradients layer-by-layer

Mnemonic — "NALOB" Neuron → Activation → Loss → Optimizer → Backprop "NALOB: Neurons Activate, Loss Optimizes Backward"

1.3 Key Activation Functions

Function Range Use Case Gotcha
ReLU [0, ∞) Hidden layers (default) Dying ReLU (outputs 0 forever)
Sigmoid (0, 1) Binary classification output Vanishing gradients
Tanh (-1, 1) Hidden layers (legacy) Vanishing gradients
Softmax (0, 1), sums to 1 Multi-class output Used in attention scores too

Mnemonic — "Real Students Take Softmax" ReLU → Sigmoid → Tanh → Softmax

1.4 Overfitting vs. Underfitting

Problem Symptom Solutions
Overfitting High train accuracy, low test accuracy Dropout, regularization (L1/L2), more data, early stopping
Underfitting Low accuracy everywhere Bigger model, more features, train longer

Mnemonic — "DROP IT" (Overfitting cures) Dropout, Regularization, Out-of-sample validation, Prune less, Increase data, Terminate early

1.5 Key Architectures

Architecture Best For Key Feature
CNN Images, spatial data Convolutional filters, pooling
RNN Sequential data Hidden state carries memory
LSTM Long sequences Gates (forget, input, output) solve vanishing gradients
Transformer NLP, modern LLMs Self-attention, parallelizable

Mnemonic — "CRLT" "CaRs Love Transformers" — CNN → RNN → LSTM → Transformer

1.6 Training Concepts

Concept Definition
Epoch One full pass through the training data
Batch Size Number of samples per gradient update
Learning Rate Step size for weight updates (too high = diverge, too low = slow)
Gradient Descent Move in the direction that reduces loss
Vanishing Gradient Gradients shrink to ~0 in deep networks → early layers don't learn

Mnemonic — "Every Batch Learns by Gradient Victory" Epoch, Batch, Learning rate, Gradient descent, Vanishing gradient


Section 2: NLP & LLM Architecture (20%)

2.1 The Transformer Architecture

The Transformer is the foundation of all modern LLMs (GPT, BERT, T5, LLaMA).

Core Idea: Replace recurrence with self-attention — process all tokens in parallel.

Input → [Embedding + Positional Encoding] → [Encoder Stack] → [Decoder Stack] → Output
Component What It Does
Input Embedding Converts tokens → dense vectors
Positional Encoding Injects word order info (sine/cosine or learned)
Multi-Head Attention Multiple attention heads capture different relationships
Feed-Forward Network Two linear layers + ReLU per position
Layer Normalization Stabilizes training
Residual Connections Skip connections to help gradient flow

Mnemonic — "Every Position Matters, Feeding Layers Right" Embedding, Positional encoding, Multi-head attention, Feed-forward, Layer norm, Residual connections

2.2 Self-Attention Mechanism (CRITICAL for exam)

Formula: Attention(Q, K, V) = softmax(QK^T / √d_k) × V

Symbol Meaning
Q (Query) "What am I looking for?"
K (Key) "What do I contain?"
V (Value) "What information do I provide?"
√d_k Scaling factor to prevent extreme softmax values

Mnemonic — "Queens Keep Valuable Secrets" Query asks, Key matches, Value delivers, Scale stabilizes

Why multi-head? Each head learns a different type of relationship (syntax, semantics, co-reference). Outputs are concatenated and projected.

2.3 Encoder vs. Decoder Models

Type Architecture Training Objective Example Best For
Encoder-only Bidirectional attention Masked Language Model (MLM) BERT Classification, NER, QA
Decoder-only Causal (left-to-right) attention Next-token prediction GPT, LLaMA Text generation
Encoder-Decoder Full Transformer Seq-to-seq T5, BART Translation, summarization

Mnemonic — "BEG-T" BERT = Encoder, GPT = Decoder, T5 = Both "BEG T5 to do both"

2.4 Tokenization

Method How It Works
Word-level Each word = 1 token (huge vocabulary)
BPE (Byte-Pair Encoding) Merges frequent character pairs iteratively (GPT uses this)
WordPiece Similar to BPE, used by BERT
SentencePiece Language-agnostic, works on raw text

Mnemonic — "Words Break into Word-Sentence Pieces" Word → BPE → WordPiece → SentencePiece

2.5 Fine-Tuning & Adaptation

Method Description When to Use
Full Fine-Tuning Update all weights Small model, lots of data
LoRA (Low-Rank Adaptation) Train small rank-decomposition matrices Large model, limited compute
P-Tuning / Prompt Tuning Learn soft prompt embeddings Very efficient, minimal changes
RLHF RL with human preference reward model Align model behavior (ChatGPT)
RAG Retrieve external docs → augment prompt Need current/private knowledge

Mnemonic — "Fine-tune LLMs Properly, Really Accurately, Guaranteed" Full fine-tuning, LoRA, Prompt tuning, RLHF, Augmented retrieval (RAG), Guardrails

2.6 Key LLM Concepts

Concept Definition
Temperature Controls randomness (0 = deterministic, 1+ = creative)
Top-k Sample from top k most likely tokens
Top-p (nucleus) Sample from smallest set whose cumulative probability ≥ p
Context Window Max tokens the model can process at once
Hallucination Model generates plausible but factually wrong content
Prompt Engineering Designing inputs to get desired outputs (zero-shot, few-shot, CoT)

Mnemonic — "Transformers Think Through Context, Handling Prompts" Temperature, Top-k/p, Context window, Hallucination, Prompt engineering


DAY 2 — NVIDIA Stack & Trustworthy AI


Section 3: NVIDIA Deployment & Tools (40%) — HIGHEST WEIGHT

3.1 The NVIDIA AI Stack at a Glance

┌─────────────────────────────────────────────┐
│            APPLICATION LAYER                │
│    NeMo (Build & Fine-tune LLMs)            │
├─────────────────────────────────────────────┤
│            INFERENCE LAYER                  │
│    Triton Inference Server (Serve models)   │
│    TensorRT (Optimize for GPU inference)    │
├─────────────────────────────────────────────┤
│            DATA LAYER                       │
│    RAPIDS: cuDF, cuML, cuGraph              │
├─────────────────────────────────────────────┤
│            HARDWARE LAYER                   │
│    NVIDIA GPUs + CUDA                       │
└─────────────────────────────────────────────┘

Mnemonic — "Never Trust Raw Hardware" NeMo (build) → Triton + TensorRT (serve) → RAPIDS (data) → Hardware (GPU/CUDA)

3.2 NVIDIA NeMo

Purpose: End-to-end framework for building, training, and fine-tuning LLMs and speech/vision models.

Feature Detail
NeMo Framework Training & fine-tuning large models at scale
NeMo Guardrails Add safety rails to LLM applications (topic control, fact-checking)
Supported models GPT, LLaMA, Falcon, Mixtral, and more
Fine-tuning methods Full, LoRA, P-Tuning, SFT, RLHF
Data parallelism Distribute training across multiple GPUs
Model parallelism Split a single model across GPUs (tensor & pipeline parallelism)

Mnemonic — "NeMo: Nice Models, Guardrailed & Parallel" Build Nice Models with Guardrails using Parallelism

3.3 Triton Inference Server

Purpose: Serve ML models at scale in production. Multi-framework, multi-model.

Feature Detail
Multi-framework PyTorch, TensorFlow, TensorRT, ONNX, custom Python
Dynamic batching Groups requests to maximize GPU utilization
Model ensemble Chain multiple models in a pipeline
Concurrent model execution Run different models simultaneously on same GPU
Model repository Organized directory structure for model management
HTTP/gRPC endpoints Standard APIs for inference requests
Metrics Prometheus metrics for monitoring

Mnemonic — "Triton Does Many Concurrent Ensembles" Triton: Dynamic batching, Multi-framework, Concurrent execution, Ensembles

Model Repository Structure:

model_repository/
├── model_name/
│   ├── config.pbtxt        # Model configuration
│   └── 1/                  # Version 1
│       └── model.plan      # TensorRT engine (or .pt, .onnx, etc.)

3.4 TensorRT

Purpose: Optimize deep learning models for maximum inference speed on NVIDIA GPUs.

Optimization What It Does
Layer Fusion Combines multiple layers into one kernel
Precision Calibration FP32 → FP16 / INT8 (faster, less memory)
Kernel Auto-Tuning Selects best GPU kernel for each operation
Dynamic Tensor Memory Reuses memory buffers efficiently
Multi-Stream Execution Parallel execution of independent ops

Mnemonic — "TensorRT: Layers Fuse Precisely, Kernels Dominate, Memory Streams" Or simply: "FLPKM"Fusion, Lower precision, Profiling, Kernel tuning, Memory optimization

Workflow:

Trained Model (.onnx/.pt) → TensorRT Optimizer → Optimized Engine (.plan) → Deploy on Triton

Exam tip: TensorRT-LLM is specifically designed for LLM inference optimization. Know the difference:

  • TensorRT = general deep learning inference optimizer
  • TensorRT-LLM = specialized for LLMs with KV-cache, in-flight batching, tensor parallelism

3.5 RAPIDS (GPU-Accelerated Data Science)

Library GPU Replacement For Purpose
cuDF Pandas GPU-accelerated DataFrames
cuML Scikit-learn GPU-accelerated ML algorithms
cuGraph NetworkX GPU-accelerated graph analytics
Dask-cuDF Dask + Pandas Multi-GPU, multi-node DataFrames

Mnemonic — "RAPIDS CUres Slow Data" cuDF, cuML, cuGraph — everything starts with "cu" = CUDA Unleashed

Key exam point: RAPIDS provides a near-identical API to Pandas/Scikit-learn — minimal code changes to go from CPU → GPU.

# CPU (Pandas)
import pandas as pd
df = pd.read_csv("data.csv")

# GPU (cuDF) — same API!
import cudf
df = cudf.read_csv("data.csv")

3.6 NVIDIA AI Enterprise & NGC

Component Purpose
NGC (NVIDIA GPU Cloud) Catalog of pre-trained models, containers, Helm charts
NVIDIA AI Enterprise Enterprise software suite for AI (support, security, management)
NVIDIA AI Foundations Cloud services for custom generative AI model building
CUDA Programming model for GPU parallel computing

Mnemonic — "NGC: NVIDIA's Grand Catalog"

3.7 Multi-GPU Training Strategies

Strategy How It Works
Data Parallelism Same model on each GPU, different data batches
Tensor Parallelism Split individual layers across GPUs
Pipeline Parallelism Split model layers into stages across GPUs
ZeRO (DeepSpeed) Partition optimizer states, gradients, and parameters

Mnemonic — "Data Travels in Pipeline Zones" Data parallelism, Tensor parallelism, Pipeline parallelism, ZeRO


Section 4: Trustworthy AI & Ethics (10%)

4.1 Core Principles

Principle Description
Fairness No bias against protected groups
Transparency Explainable decisions
Privacy Data protection, differential privacy, federated learning
Safety Guardrails against harmful outputs
Accountability Clear ownership of AI decisions
Robustness Resistant to adversarial attacks

Mnemonic — "FTP-SAR" Fairness, Transparency, Privacy, Safety, Accountability, Robustness "FTP your SAR (Safety Assurance Report)"

4.2 Bias & Mitigation

Bias Type Where It Occurs Mitigation
Data Bias Training data over/under-represents groups Balanced datasets, data augmentation
Algorithmic Bias Model learns biased patterns Fairness constraints, bias audits
Evaluation Bias Metrics don't capture fairness Use disaggregated metrics per group

4.3 NeMo Guardrails (Exam Favorite)

What: A toolkit for adding programmable constraints to LLM applications.

Feature Purpose
Topical Guardrails Keep conversations on-topic
Safety Guardrails Block harmful/toxic content
Security Guardrails Prevent prompt injection, jailbreaks
Fact-Checking Rails Verify outputs against knowledge base
Colang NVIDIA's modeling language for defining conversational guardrails

Mnemonic — "Guard TSSF with Colang" Topical, Safety, Security, Fact-checking — written in Colang


Quick-Reference Cheat Sheet

Tool → Purpose (One-liner)

Tool Remember As
NeMo "Build and fine-tune"
Triton "Serve models at scale"
TensorRT "Optimize for fast inference"
RAPIDS/cuDF "GPU DataFrames (drop-in for Pandas)"
cuML "GPU Scikit-learn"
NGC "Model/container catalog"
NeMo Guardrails "Safety rails for LLM apps"
Colang "Language for writing guardrails"
RLHF "Align model with human preferences"
LoRA "Efficient fine-tuning with small matrices"
RAG "Retrieve external knowledge to reduce hallucination"

Master Mnemonic: The NVIDIA AI Pipeline

"Build → Optimize → Serve → Accelerate Data" NeMo → TensorRT → Triton → RAPIDS "Bots Only Serve Awesome Data"


Exam Tips

  1. Time management: ~1 minute per question. Don't overthink — flag and move on.
  2. NVIDIA tools make up 40% — know what each tool does and when to use it.
  3. Transformer attention formula will likely appear: softmax(QK^T / √d_k) × V
  4. cuDF vs. Pandas — remember: same API, GPU-accelerated, that's the selling point.
  5. Triton dynamic batching — the #1 feature for production inference scaling.
  6. NeMo Guardrails + Colang — expect 2-3 questions on this.
  7. TensorRT optimizations — layer fusion and precision reduction (FP16/INT8) are the key points.
  8. RLHF flow: Pre-train → SFT → Reward Model → PPO fine-tuning.
  9. Encoder vs. Decoder: BERT = understanding, GPT = generation. If the question is about classification → encoder. Generation → decoder.
  10. RAG vs. Fine-tuning: RAG for current/external knowledge, fine-tuning for behavior/style changes.

Mock Exam — Practice Questions & Answers

Q1 — ML Foundations

Which type of learning does GPT use during pre-training? A) Supervised Learning | B) Reinforcement Learning | C) Self-Supervised Learning | D) Unsupervised Learning

Answer: C — GPT uses next-token prediction, creating its own labels from raw text. That's self-supervised. Mnemonic: "SUSS-R" — GPT pre-trains on "Self"

Q2 — Transformer Architecture

In Attention(Q,K,V) = softmax(QK^T / √d_k) × V, what is the purpose of dividing by √d_k? A) Normalize output values | B) Prevent large dot products pushing softmax into tiny-gradient regions | C) Reduce key dimensionality | D) Convert to probabilities

Answer: B — Large dot products → near-one-hot softmax → vanishing gradients. Scaling keeps values stable. Mnemonic: "Queens Keep Valuable Secrets" — without Scale, the Secret (gradient) vanishes

Q3 — NVIDIA Tools

What is the primary purpose of NVIDIA Triton Inference Server? A) Fine-tuning LLMs with LoRA | B) Layer fusion and precision reduction | C) Serving ML models at scale with multi-framework support and dynamic batching | D) GPU-accelerated data preprocessing

Answer: C — Triton = production serving. NeMo = fine-tuning, TensorRT = optimization, RAPIDS = data. Mnemonic: "Triton Does Many Concurrent Ensembles"

Q4 — Neural Networks

A model gets 98% train accuracy but 62% test accuracy. What is this, and what helps? A) Underfitting — increase complexity | B) Overfitting — apply dropout and regularization | C) Vanishing gradients — use ReLU | D) Overfitting — increase learning rate

Answer: B — High train + low test = overfitting. Dropout & regularization help generalize. Mnemonic: "DROP IT" — Dropout, Regularization, Out-of-sample, Prune less, Increase data, Terminate early

Q5 — LLM Architecture

Which model type for text classification (sentiment analysis)? A) Decoder-only (GPT) | B) Encoder-only (BERT) | C) Encoder-Decoder (T5) | D) RNN (LSTM)

Answer: B — BERT uses bidirectional attention = understands full context = ideal for classification. Mnemonic: "BEG T5 to do both" — BERT=Encoder(understands), GPT=Decoder(generates), T5=Both

Q6 — NVIDIA Tools

Which RAPIDS library is a GPU-accelerated drop-in replacement for Pandas? A) cuML | B) cuGraph | C) cuDF | D) Dask

Answer: C — cuDF = CUDA DataFrames. Same API as Pandas, runs on GPU. Mnemonic: "RAPIDS CUres Slow Data" — cuDF = cuDA DataFrames

Q7 — Fine-Tuning

Adapt a 70B param LLM with limited GPU resources. Best method? A) Full fine-tuning | B) Train from scratch | C) LoRA | D) Increase context window

Answer: C — LoRA freezes original weights, trains small matrices. Low resources = LoRA. Mnemonic: "LoRA = Low Resources Allowed"

Q8 — TensorRT

Which is NOT a TensorRT optimization? A) Layer fusion | B) Precision calibration | C) Dynamic batching | D) Kernel auto-tuning

Answer: C — Dynamic batching is Triton (serving), not TensorRT (model optimization). Mnemonic: "TensorRT optimizes the MODEL. Triton optimizes the SERVING."

Q9 — Trustworthy AI

What is NeMo Guardrails, and what language defines its rules? A) Training framework; Python | B) Safety constraints toolkit; Colang | C) Inference optimizer; YAML | D) Bias detection; JSON

Answer: B — NeMo Guardrails adds programmable safety rails. Rules written in Colang. Mnemonic: "Guard TSSF with Colang" — Topical, Safety, Security, Fact-checking

Q10 — Attention Mechanism

Multi-head attention: 8 heads, model dim 512. Dimension per head? A) 512 | B) 64 | C) 8 | D) 4096

Answer: B — 512 ÷ 8 = 64. Each head gets an equal slice, outputs concatenated back. Mnemonic: "Heads Divide, then Concatenate"

Q11 — NVIDIA Tools

In NVIDIA's AI workflow, what is the correct order from training to production? A) Triton → TensorRT → NeMo | B) NeMo → TensorRT → Triton | C) TensorRT → NeMo → Triton | D) NeMo → Triton → TensorRT

Answer: B — Build (NeMo) → Optimize (TensorRT) → Serve (Triton). Always optimize before serving. Mnemonic: "Bots Only Serve Awesome Data" — Build → Optimize → Serve

Q12 — Self-Supervised Learning

BERT's MLM is self-supervised rather than supervised because? A) Requires human annotators | B) Model generates its own labels by masking and predicting tokens | C) Uses RL with reward signal | D) Clusters sentences without labels

Answer: B — The original tokens ARE the labels. GPT = next-token, BERT = masked-token. Both self-label. Mnemonic: "Self = Self-labeling"

Q13 — Encoder vs Decoder

Automated customer support chatbot that generates human-like responses. Which architecture? A) Encoder-only (BERT) | B) Decoder-only (GPT) | C) Encoder-Decoder (T5) | D) CNN

Answer: B — Chatbot generates new text = Decoder (GPT). BERT = understand, T5 = transform text→text. Mnemonic: "BERT Understands, GPT Generates, T5 Transforms"

Q14 — TensorRT vs Triton

Reduce inference latency by converting FP32 to FP16. Which tool? A) Triton | B) NeMo | C) TensorRT | D) RAPIDS cuML

Answer: C — Precision calibration is model optimization = TensorRT's job. Mnemonic: "FLPKM" — Fusion, Lower precision, Profiling, Kernel tuning, Memory optimization

Q15 — RLHF

Correct order of RLHF pipeline steps? A) Reward Model → Pre-training → SFT → PPO | B) Pre-training → SFT → Reward Model → PPO | C) SFT → Pre-training → PPO → Reward Model | D) Pre-training → PPO → Reward Model → SFT

Answer: B — Pre-train → SFT → Reward Model → PPO. How ChatGPT was built. Mnemonic: "Please Stop Reviewing Poorly" — Pre-train → SFT → Reward → PPO

Q16 — RAG vs Fine-Tuning

Legal firm needs LLM to answer from private, frequently updated case law. Best approach? A) Full fine-tuning | B) LoRA | C) RAG | D) Increase temperature

Answer: C — Private + frequently updated = RAG. Fine-tuning bakes static knowledge into weights. Mnemonic: "RAG = Real-time Access to Grounded knowledge"

Q17 — Multi-GPU Training

175B model can't fit on one GPU. Which strategy splits individual layers across GPUs? A) Data Parallelism | B) Tensor Parallelism | C) Pipeline Parallelism | D) Gradient Accumulation

Answer: B — Tensor = split WITHIN a layer. Pipeline = split BETWEEN layers. Data = split the data. Mnemonic: "Tensor = split the Tensor (inside layer)"

Q18 — Triton Inference Server

Which Triton feature groups multiple incoming requests to maximize GPU utilization? A) Model ensemble | B) Concurrent model execution | C) Dynamic batching | D) Model versioning

Answer: C — Dynamic batching groups requests on-the-fly. Triton's #1 production feature. Mnemonic: "Triton Does Many Concurrent Ensembles" — D = Dynamic batching

Q19 — Tokenization

GPT models use which tokenization method? A) Word-level | B) Character-level | C) BPE | D) WordPiece

Answer: C — GPT = BPE (Byte-Pair Encoding). BERT = WordPiece. T5/LLaMA = SentencePiece. Mnemonic: "Good Pairs Together = Byte Pair Encoding"

Q20 — NeMo Guardrails

Banking chatbot needs to prevent off-topic discussions. Which guardrail? A) Safety Guardrails | B) Security Guardrails | C) Topical Guardrails | D) Fact-Checking Rails

Answer: C — Staying on-topic = Topical Guardrails. Safety = block harm, Security = block attacks. Mnemonic: "Guard TSSF with Colang" — Topical, Safety, Security, Fact-checking

Q21 — Activation Functions

Most common activation function in the output layer of multi-class classification? A) ReLU | B) Sigmoid | C) Tanh | D) Softmax

Answer: D — Softmax outputs probabilities summing to 1. Sigmoid = binary, ReLU = hidden layers. Mnemonic: "Single class? Sigmoid. Multiple classes? SoftMax."

Q22 — NVIDIA Ecosystem

Where to download pre-trained models, GPU-optimized containers, and Helm charts? A) RAPIDS | B) NGC | C) NeMo | D) CUDA Toolkit

Answer: B — NGC = NVIDIA's Grand Catalog. One-stop shop for models, containers, charts. Mnemonic: "NGC: NVIDIA's Grand Catalog"

Q23 — Encoder vs Decoder

Extract disease names from medical records (NER). Which architecture? A) Decoder-only (GPT) | B) Encoder-only (BERT) | C) Encoder-Decoder (T5) | D) GAN

Answer: B — NER = labeling/classifying tokens = understanding = BERT (Encoder). Mnemonic: "BERT = Brain that Examines and Reads Text"

Q24 — Loss Functions

Most appropriate loss function for binary classification? A) MSE | B) Binary Cross-Entropy | C) Categorical Cross-Entropy | D) MAE

Answer: B — Cross-Entropy for Classification, MSE for Measurement (regression). Mnemonic: "Cross for Class, MSE for Measure"

Q25 — TensorRT-LLM

What distinguishes TensorRT-LLM from standard TensorRT? A) TensorRT-LLM is for training | B) Adds KV-cache, in-flight batching, tensor parallelism for LLMs | C) Only supports PyTorch | D) Replaces Triton

Answer: B — TensorRT-LLM = TensorRT + KIT (KV-cache, In-flight batching, Tensor parallelism). Mnemonic: "TensorRT-LLM = TensorRT + KIT"

Q26 — Vanishing Gradients

Which architecture was designed to solve vanishing gradients in sequential models? A) CNN | B) Standard RNN | C) LSTM | D) Autoencoder

Answer: C — LSTM uses three gates (Forget, Input, Output) to control gradient flow. Mnemonic: "LSTM = Long-term Saving Through Memory gates" — FIO fixes the flow

Q27 — Prompt Engineering

Developer provides 3 example input-output pairs before asking LLM to perform a task. What technique? A) Zero-shot | B) Few-shot | C) Chain-of-Thought | D) RAG

Answer: B — Providing examples = few-shot. CoT = step-by-step reasoning, not examples. Mnemonic: "Counting examples? Shot-counting. Showing reasoning? CoT."

Q28 — RAPIDS cuML

Data scientist needs GPU-accelerated, API-compatible alternative to Scikit-learn's RandomForest? A) cuDF | B) cuGraph | C) cuML | D) Dask-cuDF

Answer: C — cuML = GPU Scikit-learn. cuDF = Pandas. cuGraph = NetworkX. Mnemonic: cuDF = DataFrames, cuML = Machine Learning, cuGraph = Graphs

Q29 — Positional Encoding

Why do Transformers need positional encoding? A) Reduce dimensionality | B) Add word order since self-attention has no inherent position sense | C) Normalize attention weights | D) Prevent overfitting

Answer: B — Self-attention treats input as a set. Positional encoding injects order. Mnemonic: "No Position = No Order = No Meaning"

Q30 — Triton Model Repository

Correct Triton model repository structure? A) models/model_name/model.pt | B) model_repository/model_name/config.pbtxt + .../1/model.plan | C) triton/models/config.yaml + .../weights.bin | D) repository/model_name/latest/model.onnx

Answer: B — config.pbtxt (not yaml) + numbered version dirs (not "latest"). Mnemonic: "pbtxt, not yaml. Numbers, not names."

Q31 — Encoder vs Decoder

Translate English to French. Which model? A) Encoder-only (BERT) | B) Decoder-only (GPT) | C) Encoder-Decoder (T5) | D) LSTM

Answer: C — Translation = REWRITE (one text into another) = Encoder-Decoder (T5). Mnemonic: "READ → BERT, WRITE → GPT, REWRITE → T5"

Q32 — Learning Rate

What happens if learning rate is set too high? A) Converges slowly but accurately | B) Overshoots optimal weights and may diverge | C) Underfits | D) Gradients vanish

Answer: B — Too high = big jumps = overshoot minimum = loss diverges. Mnemonic: "High = Hyper jumps, Low = Lazy crawls"

Q33 — NeMo Framework

Which is NOT a NeMo capability? A) Training LLMs from scratch | B) Fine-tuning with LoRA/P-Tuning | C) Real-time serving with dynamic batching | D) Data and tensor parallelism

Answer: C — Serving = Triton. NeMo builds and trains, never serves. Mnemonic: "NeMo Never Serves"

Q34 — Hallucination

Most effective approach to reduce hallucinations for company-specific data? A) Increase temperature | B) Larger model | C) RAG | D) More attention heads

Answer: C — RAG grounds responses in retrieved documents. Higher temp = more hallucination. Mnemonic: "RAG = Real Answers, Grounded"

Q35 — Dropout

During training, dropout sets 50% of neurons to zero. What happens at inference? A) Dropout continues | B) Dropout off, all neurons active, weights scaled | C) Only surviving neurons used | D) Dropout rate doubled

Answer: B — Dropout is training-only. At inference, full capacity with scaled weights. Mnemonic: "DROP at Train, FULL at Test"

Q36 — Model Parallelism

Layers 1-20 on GPU1, 21-40 on GPU2, 41-60 on GPU3. What type of parallelism? A) Data | B) Tensor | C) Pipeline | D) ZeRO

Answer: C — Groups of layers split across GPUs = Pipeline. Single layer split = Tensor. Mnemonic: "Pipeline = split between layers (stages in a pipe)"

Q37 — Context Window

50,000 token document into a 32,000 token context window. What happens? A) Model auto-summarizes | B) Input truncated or request fails | C) Multi-pass automatically | D) Extra tokens stored in memory

Answer: B — Context window is a hard limit. No auto-summarization or memory. Mnemonic: "Context Window = Hard Wall"

Q38 — Triton Ensemble

Triton deployment needs preprocessing → inference → postprocessing in one request. Which feature? A) Dynamic batching | B) Model ensemble | C) Concurrent execution | D) Model versioning

Answer: B — Model ensemble chains models into a single pipeline. Mnemonic: "Ensemble = End-to-end pipeline"

Q39 — Federated Learning

5 hospitals want to train AI without sharing patient data. Which approach? A) Transfer learning | B) Data parallelism | C) Federated learning | D) Data augmentation

Answer: C — Federated learning trains locally, shares only model updates (gradients), never raw data. Mnemonic: "Data stays home, only gradients travel"

Q40 — Encoder vs Decoder (Matching)

Match: 1) Summarize article, 2) Generate Python code, 3) Detect spam A) 1: Enc-Dec, 2: Decoder, 3: Encoder | B) 1: Decoder, 2: Encoder, 3: Enc-Dec | C) 1: Encoder, 2: Decoder, 3: Enc-Dec | D) 1: Enc-Dec, 2: Encoder, 3: Decoder

Answer: A — Summarize = REWRITE (T5), Generate code = WRITE (GPT), Detect spam = READ (BERT). Mnemonic: "READ → BERT, WRITE → GPT, REWRITE → T5"


Progress Tracker — 40/50 Questions

Domain Correct Total Accuracy
ML Foundations 7 10 70%
NLP/Transformers 8 13 62%
NVIDIA Tools 10 12 83%
Trustworthy AI 3 3 100%
Fine-Tuning/RLHF 3 3 100%
Overall 28 40 70%

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NVIDIA Generative AI & LLMs Associate (NCA-GENL)

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