Science Project on “Levels of Humidity”, Project Experiment Topics on Environmental Science for Class 8, 9, 10 and 12 Students.

Levels of Humidity

Materials Required:

1. Two rulers
2. Two pieces of cloth, 4 inches (10 cm) square
3. Six thumbtacks

4. 2 pencils
5. Safety scissors
6. Eye-dropper
7. Paper
8. Clock or watch

In the air around us, there are tiny droplets of moisture. This moisture in the air is called Humidity. If there is a lot of moisture in the air, we say that the humidity is high. When someone takes a hot shower, the room steams up. We can easily see that the humidity in the bathroom is high.

Can you guess what is the humidity level in your room today? Is it higher or lower than it is outside? Cut two squares out of an old piece of cloth. Each piece should be four inches (10 cm) square. Fold each piece in half twice.

Once you finish preparing the cloth, lay a pencil on the table. Set a ruler across the pencil, just around the middle, to resemble a seesaw. Place one of the folded pieces of cloth, at one end of the ruler. Move the pencil slowly under the ruler, until it balances as well as possible. Now place another thumbtack upside down, near the end of the ruler that does not have the piece of cloth over it. This will weigh down that end. We now know that when the cloth is dry, the other end of the ruler will be heavier.

Fill an eyedropper with water. Slowly squeeze drops of water onto the cloth, until the ruler tips and the water-soaked side of the cloth is now the heavier side. Be sure to count the number of drops you squeeze. Note down the time. Keep checking the ruler balance. When the side of the ruler, with the two thumbtacks touches the table, write down the time again. How long did it take for the moisture to dry out of the cloth?

Make another seesaw ruler outside, just like the one made previously. Squeeze the same amount of water droplets onto the cloth as you did inside. Write down the time and keep checking the balance. When the side of the ruler with the two thumbtacks touches the table, write down the time.

If the air inside is drier than the air outside, the water on the cloth in the house will evaporate and the cloth will dry quicker than the water on the cloth outside. Did you guess it right? Is there any difference in the humidity of the air, outside on a sunny day, as compared to what it would be on a cloudy day? Is there any difference in the humidity of the air, during the day compared to at the night?

THERMOMETERS

Thermometers are used to measure temperature. Though there are various types of thermometers, the simplest type is made up of a glass tube which is sealed at the top end and has a bulb filled with mercury on the bottom end.

Whenever any solid, liquid or gas heats, it expands. This universal principle is applied to the working of a thermometer. As the temperature in the air rises, it expands the mercury in the bulb and it rises up the glass tube. The tube has a temperature scale marked upon it. When you read the scale up to which the mercury has risen, you come to know the temperature. Yet another variety of thermometer is called a resistance thermometer, changes in temperature cause variations in an electric current that flows through it.