From Factory Floor to Cloud

सम्यक् उत्तराणि अत्र न दर्श्यन्ते, अतः क्रीडायां तानि आश्चर्यम् एव भविष्यन्ति।

1. प्रश्नः 1

   Which industrial protocol is the vendor-neutral standard often used to read data from PLCs?

   • OPC UA
   • SNMP
   • SMTP
   • LDAP

2. प्रश्नः 2

   In MQTT, what does a client connect to in order to publish and subscribe?

   • A topic server
   • A broker
   • A gateway hub
   • A message queue

3. प्रश्नः 3

   A sensor reading must arrive exactly once, with no duplicates. Which MQTT QoS level guarantees this?

   • QoS 1 with retain
   • QoS 1
   • QoS 2
   • QoS 3

4. प्रश्नः 4

   How does a device usually authenticate to AWS IoT Core over MQTT?

   • Username and password
   • Shared API key
   • IP allow-list
   • X.509 client certificate

5. प्रश्नः 5

   Old PLCs speak Modbus only. Where is the data typically translated to MQTT?

   • Inside AWS IoT Core
   • On an edge gateway
   • In the MQTT broker
   • In the cloud database

6. प्रश्नः 6

   Which AWS IoT Core feature routes incoming messages to services like S3, Lambda or Kinesis?

   • Rules engine
   • Device shadow
   • Fleet indexing
   • Job service

7. प्रश्नः 7

   An app needs a machine's last reported state even while the machine is offline. What fits best?

   • A retained topic in S3
   • A Lambda cache layer
   • A Device Shadow
   • A Kinesis stream

8. प्रश्नः 8

   The factory's internet link drops for an hour. What prevents data loss at the edge?

   • Higher MQTT QoS in the cloud
   • A larger cloud broker
   • Shorter keep-alive timers
   • Store-and-forward buffering

9. प्रश्नः 9

   Why is a robot's emergency stop kept in the PLC rather than run from the cloud?

   • Cloud bills are too high
   • Latency must be deterministic
   • MQTT can't carry booleans
   • AWS forbids control use

10. प्रश्नः 10

    In the ISA-95 model, which level holds the sensors and actuators themselves?

    • Level 0
    • Level 2
    • Level 3
    • Level 4