Embedded Systems & IoT MCQ
Test your Embedded Systems & IoT knowledge with 100 multiple choice questions covering fundamentals to advanced concepts, with instant feedback and explanations.
What is an "embedded system"?
2What does "IoT" stand for?
3What is a "microcontroller" (MCU)?
4What is the main difference between a microcontroller and a microprocessor?
5What is "firmware"?
6What is GPIO (General Purpose Input/Output)?
7What is the difference between "analog" and "digital" signals?
8What does an ADC (Analog-to-Digital Converter) do?
9What is the purpose of a "sensor" in an IoT device?
10What is an "actuator" in an embedded/IoT system?
11What is the purpose of an "interrupt" in embedded systems programming?
12What is "polling" in embedded systems, and how does it differ from using interrupts?
13What is the purpose of a "real-time clock" (RTC) module in an embedded system?
14What is the difference between "RAM" and "flash memory" (ROM) in a microcontroller?
15What is PWM (Pulse Width Modulation) commonly used for in embedded systems?
16What is the purpose of a "bootloader" in an embedded device?
17What is UART (Universal Asynchronous Receiver-Transmitter) commonly used for?
18What is I2C (Inter-Integrated Circuit) used for in embedded systems?
19What is SPI (Serial Peripheral Interface) commonly used for?
20What is a "real-time operating system" (RTOS)?
21What is the difference between a "hard real-time" and "soft real-time" system?
22What is the role of a "watchdog timer" in an embedded system?
23What is "Wi-Fi" commonly used for in IoT devices?
24What is "Bluetooth Low Energy" (BLE) primarily designed for?
25What is "MQTT" commonly used for in IoT?
26What does "low power mode" or "sleep mode" allow an embedded device to do?
27What is the purpose of "debouncing" when reading a mechanical button or switch?
28What is a "development board" like Arduino or Raspberry Pi commonly used for?
29What is the difference between Arduino and Raspberry Pi in terms of typical use?
30What is "OTA" (Over-The-Air) update in the context of IoT devices?
31What is a "data logger" in the context of embedded/IoT devices?
32What is "edge computing" in the context of IoT?
33What is the role of a "voltage regulator" in an embedded circuit?
34What is the purpose of "pull-up" and "pull-down" resistors in digital circuits?
35What is the difference between "volatile" and "non-volatile" memory?
36What is the purpose of "cross-compilation" in embedded development?
37What is "JTAG" commonly used for in embedded hardware development?
38What does "ESP32" / "ESP8266" refer to in the IoT hobbyist and commercial ecosystem?
39What is the purpose of an "oscillator" or "crystal" component on a microcontroller board?
40What is the purpose of a "breadboard" in embedded hardware prototyping?
In a memory-constrained microcontroller, why might a developer prefer statically allocated memory over dynamic allocation (malloc/free)?
2What is "Direct Memory Access" (DMA) and why is it useful in embedded systems?
3In an RTOS, what is the difference between "preemptive" and "cooperative" multitasking?
4What is "priority inversion" in real-time systems, and why is it a problem?
5What is a "race condition" in the context of embedded systems with interrupts or multiple tasks?
6Why is the "volatile" keyword important when declaring a variable that is modified by an interrupt handler in C for embedded systems?
7What is the purpose of a "bootrom" or "first-stage bootloader" in modern SoCs (System on Chip)?
8What is the difference between "Wi-Fi", "Zigbee", and "LoRa" in terms of typical IoT use cases?
9What is the purpose of a "CAN bus" (Controller Area Network) commonly used in automotive embedded systems?
10What is "memory-mapped I/O"?
11What is "power gating" in low-power embedded system design?
12What is the purpose of "device drivers" (e.g., in Linux-based embedded systems)?
13In IoT security, why is "secure boot" important for connected devices?
14What is "TLS" (Transport Layer Security) used for in IoT device communication?
15What challenge does "firmware over-the-air" (FOTA) update introduce for resource-constrained devices, and how is it commonly addressed?
16What is the purpose of a "level shifter" when interfacing two ICs operating at different voltage levels (e.g., 3.3V and 5V)?
17What is "task scheduling" in an RTOS typically based on, when using "rate monotonic scheduling" (RMS)?
18What is the role of a "communication protocol stack" (e.g., TCP/IP stack) on a constrained IoT device?
19Why might an embedded developer choose to write critical sections of code in assembly language rather than C?
20What is "brown-out detection" in a microcontroller, and why is it useful?
21What is the purpose of a "digital filter" (e.g., moving average) applied to sensor readings in embedded systems?
22What is the significance of "endianness" (big-endian vs little-endian) in embedded systems communication?
23What is "ESD" (Electrostatic Discharge) protection used for in embedded hardware design?
24What is the difference between "lossy" and "lossless" data compression, and which might be preferred for transmitting sensor telemetry from a constrained IoT device?
25What is the purpose of a "state machine" design pattern commonly used in embedded firmware?
26Why might an IoT device use a "local gateway" device between sensors and the cloud, rather than connecting each sensor directly to the internet?
27What is the purpose of "watchdog reset cause" registers found in many microcontrollers?
28What does "deterministic latency" mean for a communication protocol used in industrial control systems?
29What is the benefit of using a "hardware abstraction layer" (HAL) in embedded firmware development?
30What is the purpose of "calibration" for sensors in embedded systems?
31What is a key consideration when choosing between a "wired" and "wireless" connection for an industrial IoT sensor?
32What is the purpose of "mutex" (mutual exclusion) primitives in an RTOS when multiple tasks share a resource?
33What is the difference between "I2C" and "SPI" in terms of wiring and addressing?
34Why is "flash memory wear leveling" important for IoT devices that frequently write data logs to flash storage?
35What is the benefit of using a "message queue" between an interrupt service routine (ISR) and a main task in an RTOS?
36What is "provisioning" in the context of deploying a fleet of IoT devices?
37What is the purpose of an "external watchdog" IC, separate from a microcontroller's built-in watchdog timer?
38What does "deep sleep" mode typically sacrifice compared to "light sleep" mode on a microcontroller, and why might this matter for wake-up time?
39Why might a developer use "circular buffers" (ring buffers) when handling streaming data from a UART or sensor in embedded systems?
40What is the significance of "checksum" or "CRC" (Cyclic Redundancy Check) fields in embedded communication protocols?
In a memory-constrained RTOS application, what is "stack overflow" and how might it manifest in unpredictable ways?
2What is the role of a "memory protection unit" (MPU) in some microcontrollers, and how does it differ from a full "memory management unit" (MMU)?
3When designing a battery-powered IoT sensor that must last years on a single battery, why is "duty cycling" combined with careful peripheral power management critical?
4What is "side-channel attack" risk in embedded security, and what is one example relevant to cryptographic operations on microcontrollers?
5In a multi-core embedded SoC running an RTOS, what additional complexity does "cache coherency" introduce when multiple cores access shared memory?
6What is "firmware rollback protection" and why is it important for IoT device security?
7When designing a sensor network using "TDMA" (Time Division Multiple Access) for channel access, what problem does it solve compared to contention-based protocols (like CSMA)?
8What is the significance of "watchdog feeding from within an interrupt service routine" being considered a bad practice in many designs?
9What design trade-off does choosing "fixed-point arithmetic" over "floating-point arithmetic" represent on a microcontroller without a hardware FPU?
10In an IoT fleet management context, what is the benefit of using "mutual TLS" (mTLS) for device-to-cloud communication, beyond standard TLS?
11What is "jitter" in the context of real-time embedded control loops, and why does it matter for systems like motor controllers?
12What is the purpose of "ECC" (Error-Correcting Code) memory in some embedded systems, especially those operating in harsh environments (e.g., aerospace)?
13When implementing a bootloader with "A/B partitioning" for OTA updates, what critical step ensures a device doesn't get permanently bricked by a bad update?
14What is the significance of "real-time trace" tools (e.g., using a debug probe with ETM/ITM on ARM Cortex-M) for diagnosing timing-related bugs?
15In designing an IoT device that must operate reliably on intermittent or unreliable cellular connectivity (e.g., NB-IoT), what architectural pattern helps ensure data is not lost during outages?
16What is the trade-off of using "Thread" or "Zigbee" mesh networking protocols versus a "star" topology for a large IoT sensor deployment?
17Why might an embedded system use a "hardware random number generator" (HRNG) instead of a pseudo-random number generator (PRNG) for cryptographic key generation?
18What does "thermal throttling" mean for an embedded SoC, and what design considerations does it impose on sustained high-performance workloads?
19What is the purpose of "differential signaling" (e.g., used in RS-485 or USB) compared to single-ended signaling, especially in noisy industrial environments?
20In a constrained device implementing a TLS handshake, why might the choice of cryptographic algorithms (e.g., ECC vs. RSA) significantly impact feasibility?