Selected MCQ

Current Question
What is a light-year a measure of?
  • A. Time
  • B. Mass
  • C. Distance
  • D. Brightness
Correct Answer: C
Explanation:
A light-year is the distance light travels in one year.
Related Question 1
In what year did the Vera C. Rubin Observatory, with its 8.4-meter telescope, see first light?
  • A. 2023
  • B. 2024
  • C. 2025
  • D. 2026
Correct Answer: C
Explanation:
It saw first light in the summer of 2025 after over a decade of construction.
Related Question 2
Which sensor type measures distance by using light pulses and time-of-flight calculations?
  • A. Ultrasonic sensor
  • B. Infrared sensor
  • C. LiDAR sensor
  • D. GPS sensor
Correct Answer: C
Explanation:
LiDAR uses laser light pulses and timing to determine distances to objects.
Related Question 3
What protocol is lightweight and commonly used for machine-to-machine communication in IoT devices?
  • A. HTTP
  • B. MQTT
  • C. FTP
  • D. SSH
Correct Answer: B
Explanation:
MQTT is a lightweight publish/subscribe protocol ideal for IoT sensors with low bandwidth.
Related Question 4
What method do astronomers use when they detect exoplanets by observing a star's light dimming at regular intervals?
  • A. Radial velocity method
  • B. Transit method
  • C. Direct imaging
  • D. Astrometry
Correct Answer: B
Explanation:
The transit method identifies exoplanets by periodic dips in a star's brightness as a planet crosses its face.
Related Question 5
Which planet in our solar system has an orbital period shorter than its rotational period (a day longer than its year)?
  • A. Mercury
  • B. Venus
  • C. Mars
  • D. Jupiter
Correct Answer: B
Explanation:
Venus rotates very slowly (a Venusian day is about 243 Earth days) compared to its 225-day orbit around the Sun.