161. What is the key feature of FreeRTOS?
- a) Preemptive scheduling with microsecond precision
- b) Graphical user interface
- c) Built-in web browser
- d) Python interpreter
Answer: A - Designed for microcontrollers with deterministic task switching.
162. Which OS is designed for ARM Cortex-M security?
- a) Zephyr RTOS with TrustZone
- b) Android Things
- c) Windows IoT Core
- d) Ubuntu Core
Answer: A - Zephyr supports ARM's secure/non-secure world isolation.
163. What is "tickless kernel" mode in embedded OS?
- a) Disables periodic interrupts to save power
- b) Removes all timing functions
- c) Uses analog clock signals
- d) Only works with RTC modules
Answer: A - Critical for battery-powered IoT devices (e.g., FreeRTOS low-power mode).
164. Which protocol is essential for IoT device management?
- a) MQTT (Message Queuing Telemetry Transport)
- b) HTTP/2
- c) FTP
- d) SMTP
Answer: A - Lightweight pub/sub protocol for constrained devices.
165. What is "Over-the-Air (OTA) updates" in embedded systems?
- a) Wireless firmware upgrades
- b) Cloud configuration sync
- c) RAM content replacement
- d) Peripheral driver updates
Answer: A - Uses dual-bank flash for failsafe updates (common in ESP32).
166. Which RTOS supports memory protection units (MPU)?
- a) Amazon FreeRTOS with MPU wrappers
- b) Contiki OS
- c) TinyOS
- d) RIOT OS
Answer: A - Isolates tasks to prevent faults from crashing system.
167. What is "edge computing" in IoT?
- a) Processing data near the source (sensors)
- b) Cloud server optimization
- c) Network router configuration
- d) Device manufacturing process
Answer: A - Reduces latency/bandwidth vs cloud-only processing.
168. Which file system is used for embedded flash storage?
- a) SPIFFS (SPI Flash File System)
- b) NTFS
- c) ext4
- d) HFS+
Answer: A - Wear-leveling for NOR/NAND flash (common in ESP8266/32).
169. What is "deterministic behavior" in RTOS?
- a) Guaranteed worst-case execution time
- b) Probabilistic task completion
- c) Random memory allocation
- d) Dynamic priority adjustment
Answer: A - Critical for industrial control systems.
170. Which toolchain compiles Zephyr RTOS applications?
- a) GCC ARM Embedded
- b) Visual Studio
- c) LLVM for Windows
- d) Java SDK
Answer: A - Supports cross-compilation for 200+ ARM/ARC/RISC-V boards.
171. What is "Trusted Execution Environment (TEE)" in IoT?
- a) Secure enclave for sensitive operations
- b) Cloud authentication service
- c) Encrypted database
- d) VPN tunneling
Answer: A - ARM TrustZone creates isolated secure world.
172. Which RTOS has built-in LoRaWAN stack?
- a) RIOT OS
- b) FreeRTOS
- c) VxWorks
- d) QNX
Answer: A - Supports low-power wide-area networks (LPWAN).
173. What is "Yocto Project" in embedded Linux?
- a) Custom Linux distribution builder
- b) Real-time kernel patch
- c) Over-the-air update system
- d) Hardware abstraction layer
Answer: A - Creates tailored images for Raspberry Pi, BeagleBone, etc.
174. Which scheduling algorithm is used in automotive RTOS?
- a) Fixed-priority preemptive (AUTOSAR OS)
- b) Round-robin
- c) Multilevel feedback queue
- d) Lottery scheduling
Answer: A - Ensures timing-critical tasks (e.g., brake control) always run.
175. What is "ROS 2" in robotics?
- a) Robot Operating System with real-time support
- b) Windows robotics toolkit
- c) Cloud AI service
- d) FPGA programming tool
Answer: A - Uses DDS for deterministic communication between nodes.
176. Which encryption is used for IoT device authentication?
- a) ECC (Elliptic Curve Cryptography)
- b) RSA-4096
- c) AES-256
- d) SHA-3
Answer: A - Preferred for constrained devices due to smaller key sizes.
177. What is "FOTA" vs "SOTA" updates?
- a) Firmware vs Software Over-The-Air
- b) Fast vs Slow updates
- c) Full vs Partial updates
- d) Factory vs User updates
Answer: A - FOTA flashes MCU, SOTA updates application layer.
178. Which RTOS is designed for RISC-V microcontrollers?
- a) Zephyr RTOS
- b) Windows CE
- c) iOS
- d) Debian Linux
Answer: A - Supports SiFive, Kendryte K210 RISC-V chips.
179. What is "MCUboot" in embedded systems?
- a) Secure bootloader for 32-bit MCUs
- b) Multicore scheduler
- c) Memory compression
- d) Cloud provisioning
Answer: A - Validates firmware signatures before execution.
180. Which tool debugs FreeRTOS tasks?
- a) Tracealyzer
- b) GDB
- c) Valgrind
- d) Wireshark
Answer: A - Visualizes task states, queues, and execution traces.