Question

Short answer questions

D. Answer in brief.
1. Give two important effects of heat,
2. Why do electric wires sag between poles on
a hot day?
3. Why are liquids used in a thermometer?
4. Name the three commonly used scales of
temperature
5. Under what conditions is it better to
use alcohol instead of mercury in a
thermometer?​

Answer 1

1-Raises the temperature.

 Increases volume

 Changes state

2-the lines are often heavily loaded because of increased power consumption and the conductors which are generally made of copper or aluminum

3-It is because the liquids like mercury and alcohol expand uniformly on increasing temperature and also contracts uniformly on decreasing the temperature. So, it gives us an accurate measure of the temperature. That's why liquids are used in the thermometer, not solids or gases.

4-Fahrenheit, Celsius, and Kelvin scales

5-Alcohol thermometers are used rather than mercury thermometers in very cold regions because alcohol has a lower freezing point than mercury. Pure ethanol freezes at -115 degrees C, while mercury freezes at -38 degrees C.