✅ Correct Answer: Lens
Source: This question is taken from the Everyday Science
✅ Correct Answer: barometer
✅ Correct Answer: Time
✅ Correct Answer: Metrology
✅ Correct Answer: Depth
✅ Correct Answer: 10 – 20
✅ Correct Answer: Distance
✅ Correct Answer: Hardness
✅ Correct Answer: Changes in the Earth’s Magnetic Field
✅ Correct Answer: Kidney failure
✅ Correct Answer: Rainfall
✅ Correct Answer: Humidity of air
✅ Correct Answer: Dobson
✅ Correct Answer: Selenium
✅ Correct Answer: 29 km/sec