Internet of Things XEE100 Quiz Answer | Stanford university

 

Introduction to Internet of Things XEE100 

Quiz Answer | Stanford university

Module 2 Knowledge Check

Q1) Which protocol is for connected vehicles ?

• V2X

Q2) Which is the wireless protocol between the turtle and the Lilypad in the baby monitoring suit ?

• Bluetooth LE

Q3) How does the ingestible sensor obtain the power for its operation ?

• Harvesting powering

Module 3 Knowledge Check

Q1) The smallest detectable signal you can reliably measure is referred to as the sensor ____.

• Resolution

Q2) The recommended working limits of sensor (max signal to min signal value) is called ____.

• Dynamic Range

Q3) The thermal time constant of a thermistor measuring temperature in liquid would determine the measurement ___.

• Bandwidth

Module 4 Knowledge Check

Q1) The capacity of small batteries tends to double every 18 months

• False

Q2) RF transmitters in IoT modules tend to be heavily duty-cycled

• True

Q3) Vibration sources are the best energy harvesting modality

• False

Q4) WIFI links tend to provide lower energy/bit than Bluetooth LE

• True

Q5) Leakage in digital circuits is not relevant for IoT applications

• False

Q6) A moderate-resolution SAR ADC can dissipate as little at 1pJ/conversion

• True

Module 5 Knowledge Check

Q1) Select the sentence which best describes the different roles in the eMbedded-Gateway-Cloud (MGC) architecture:

• Gateway devices bridge between low-power wireless links to embedded devices and the broader Internet to the cloud.

Q 2) 6lowpan is:

• a. A collection of standards for using IPv6 over low-power wireless links

Q3) Generic ATTributes (GATT) are:

• A mechanism for naming IoT resources over Bluetooth Low Energy (BLE)

Q4) Typical ranges in 2017 for flash (code) and RAM memory in a CortexM micro controller are:

• 16kB-512kB code, 2kB-128kB RAM

Q5) Which answer best describes the circumstances when transition energy can become a significant fraction of an energy budget ?

• High-power peripherals are turned on often, for small bits of work

Q6) Suppose a device has a sleep current of 20uA and an active current of 20mA. It wakes up ten times a second (10Hz) for 1 millisecond on each waking. Assume the transition time between asleep and awake is instantaneous. What fraction of the device’s energy budget is spent *in the sleep state* ?

• 9.1%

Q7) This extends question 6. Suppose that the application, rather than wake up 10 times a second for 1ms can batch its operations to make up twice a second for 2ms. What fraction of the device’s energy budget is now spent in the sleep state ?

• 20%

Q8) What is the principal cost/drawback of a threaded execution model ?

• Requires RAM for each thread stack

Module 6 Knowledge Check

Q1) The number of connected nodes has increased by roughly 10X with each generation of wireless system (wireless telegraph, broadcast TV and radio, cellular systems)

• False

Q2) The capacity of an additive-white Gaussian noise channel with an average power constraint at the transmitter is well understood.

• True

Q3) Energy harvesting leads to dynamic energy constraints at the transmitter.

• True

Q4) The Aloha protocol does not require an acknowledgment mechanism for collisions and retransmission of messages

• False

Q5) Group testing schemes can be used to design collision-resilient multiple access codes.

• True