# Experiment on the Effect of Heat on Magnetism

### Aim:

To show that the magnetic force changes with increase or decrease in temperature of the magnet.

### Materials Required:

1. A medium sized magnet.
2. Gem clips.
3. Blow dryer.
4. Refrigerator.

### Procedure:

1. Bring the magnet close to the gem clips. Some of them will be attracted to the magnet. Count the no. of clips that gets attached to the magnet.
2. Now keep the magnet in the refrigerator, preferably the freezer section, for about 20 minutes. Now bring the cold magnet close to the gem clips again. Check how many clips are attracted by this cold magnet.
3. Use blow dryer to increase the magnet’s temperature by blowing hot air on the magnet for about 10 minutes. Now bring this hot magnet close to the gem clips again. Check how many of clips are attracted.

### Scientific Explanation:

We see that the unchanged magnet picked up the most no. of clips. On the other hand the frozen and the hot magnet picked up less no. of clips. The frozen and the heated magnet picked up approximately 10% and 20% less no. of clips, respectively. Thus, both heating and freezing the magnet decreased its strength. Heating the magnet decreased the magnet’s strength the most because the hot magnet picked up almost two times less than the frozen magnet.

# How Snoring Works

### Aim:

The aim of this fun science fair project for kids is to conduct a simple experiment to understand how snoring works.

### Materials required:

1. A sheet of wax paper.
2. A ruler.
3. A pair of scissors.

### Procedure:

1. Cut out a 15 cm or 6 inch square piece of wax paper.
2. Hold the paper by the sides and bring it up to your lips.
3. Hum a tune and observe the sound.

### Scientific explanation:

When you hum a tune with the wax paper up against your lips, the wax paper starts vibrating. This creates a sound which is similar to the sound of snoring. Snoring is caused by vibration of soft tissues inside the mouth. When you are sleeping, the hanging piece of skin at the top of the throat comes down because of gravity and blocks the airway a little. When you breathe, the air flow causes the soft tissue to vibrate like the wax paper in the experiment, thereby creating the characteristic snoring sound.

# Air Compression – Pop a Straw

### Aim:

The aim of this science fair project is to understand the effects of compressed air with a simple experiment.

### Materials required:

A thick plastic straw.

### Procedure:

1. Take the straw in both hands and tightly pinch both ends.
2. Twist the straw into coils with a motion like pedalling a bicycle. Leave an inch of untwisted straw on each end.
3. Ask somebody else to flick a finger hard at the untwisted part of the straw, hitting it with a fingernail.
4. The straw will make a loud pop.

### Scientific explanation:

As you twist the straw, the air in it gets compressed in a small space in the coils. When your friend flicks a fingernail at the straw, it gets compressed more very rapidly resulting in the walls of the straw bursting.

# Hanging Water Experiment

### Aim:

The aim of this project is to demonstrate the power of atmospheric pressure by a fun experiment.

### Materials required:

1)      A piece of paper

2)      Water

3)      An empty bottle

### Procedure:

1)      Fill the water in the bottle until it overflows

2)      Cove the mouth of the bottle with a small piece of paper. Just place the paper over the mouth of the bottle and tap on it.

3)      Keep the paper in position with your hand and slowly turn the bottle upside down.

4)      Remove your hand from the paper; you will see that it stays in position without spilling the water.

Note:

Make sure that the paper is larger than the mouth of the bottle.

Make sure that the paper completely seals the mouth of the bottle when you cove it.

Refrain yourself from shaking the bottle.

### Result:

The water is contained inside the bottle without spillage.

### Scientific Explanation:

The air pressure outside the bottle prevents the water spillage by pushing the paper to the mouth. This is possible because the downward pressure on the paper exerted by the water is lesser than the upward pressure exerted by air on the paper.

# The Floating Paper Clips Experiment

### Aim:

The aim of this science fair project is to float a paper clip on water.

### Materials Required:

1. A bowl of water
2. Tissue paper of size 8cm x 8cm (or any similar size)
3. A pencil or pen with a flat end.
4. A dry paper clip

### Procedure:

1. Fill the bowl with water till it is full
2. Try floating the paper clip, surely it will sink.
3. Take the tissue paper and float it on the water.
4. Now carefully place the paper clip on the tissue paper.
5. Now without touching the paper clip sink the tissue paper with the flat edge of the pencil or pen.
6. You will see that the paper clip is floating.

Note: It may take several tries to sink the tissue paper and float the paper clip. Try not to disturb the bowl anyway.

### How does this happen?

The paper clip floats because of a phenomenon called surface tension. Surface tension creates a sort of skin over the water surface. This ‘skin’ of water will hold your paper clip. But as the force of surface tension is very weak the ‘skin’ can break at the slight disturbance.

# Visible Light Spectrum

### Aim:

To split the white light into its constituent visible spectral colours through the following experiment.

### Materials required:

1.      A sized piece of white paper or a white cardboard.

2.      A mirror small in size.

3.      A shallow dish/pan large enough to hold the mirror horizontally

4.      Water and an outdoor sunny place.

### Procedure:

1.      Fill the dish with water.

2.      Place it on any flat surface like table or floor, directly under sunlight.

3.      Now submerge the mirror in the water completely with the shiny surface facing sunlight.

4.      Hold the paper above it in and then accordingly adjust the paper as well as the mirror till the reflection of sunlight shines on the white paper.

5.      Observe the resulting spectrum.

### Scientific explanation:

White light is a combination of light of different colours. So when light is made to pass from air to water the speed and direction of its constituent colours are affected. This is called refraction. This results in bending of light of different colours and it depends on the speed with which it travels through water. All the colours have the same speed in air but when it comes to water Red light travels the fastest and therefore bends the least. On the other hand, Violet light bends the most as it slows the most in water. Thus this phenomenon is called refraction of white light which results in a visible colourful spectrum.

# Creati a Mist of Water

### Aim:

The aim of this kid’s science fair project is to create a small mist.

### Materials Required for the project:

1. Two straws (A smaller one and a regular one)
2. A small jar of water.

### Procedure:

1. With one hand hold the smaller straw vertically in the water.
2. Take the other straw and hold it in 90 degree to the tip of the first straw.
3. Now blow through the second straw.
4. The water will rise through the vertical straw and spews out like a mist.

### Scientific Explanation:

When you blow, the air at the top of the vertical straw moves fast. This fast moving of air creates a low pressure area and the water in the jar will rise to the top of the vertical straw. This water is then carried away by the fast moving air creating a fine mist.

Note: The smaller the vertical straw the easier will be the experiment.

# Understanding the Workings of a Doorbell

### Aim:

To do a simple experiment to understand the working of a ding dong bell.

### Materials required:

1. A few feet of insulated wire.
2. A 6 volt battery.
3. A cardboard of plastic tube.
4. A big nail.

### Procedure:

1. Wrap the insulated wire around the tube making as many loops as possible. Leave the ends free.
2. Strip off the insulation from the ends of the wire and keep them ready to be connected to the terminals of the battery.
3. Insert the nail partly into the coil and connect the wire to the battery terminals briefly. You will observe that the nail is sucked into the coil.
4. Reverse the connections to the battery and repeat the experiment. Again you will see that the nail is sucked into the coil.

### Scientific explanation:

When electricity flows throw a conductor it generates a magnetic field around it. A loop of wire generates a magnetic field through the loop. When the wire is made into a coil, the strength of the magnetic field increases as the number of loops increases and the assembly acts as a strong electromagnet. Hence when the battery is connected to the coil and the electromagnet turns on, the nail is quickly sucked in. This is exactly what happens in a ding dong bell. In a real bell a plate is kept for the nail to strike as it is sucked in, thereby creating a ringing sound. Even when you reverse the direction of current, the iron nail is still sucked in as the iron atoms reorient so that they line up with opposite poles to the electromagnets. Therefore the nail is always attracted and pulled in by the coil electromagnet.

# Testing the Efficiency of Two Light Sources

### Aim:

The aim of this science fair project is to compare different light sources and deduce which one is more energy efficient using a simple experiment.

### Materials required:

1. A normal incandescent light bulb.
2. A florescent light bulb.
3. A lamp with an easy to remove light bulb holder.
4. A thermometer.

### Procedure for the project:

1. Fix the incandescent bulb to the lamp and switch on the lamp.
2. Hold the thermometer around six inches away from the bulb for a minute and note down the temperature reading. Also observe the light.
3. Switch off the lamp and replace the bulb with the florescent bulb after it cools down. Turn the lamp back on.
4. Measure the temperature and observe the light just like before.

### Scientific explanation:

The incandescent light bulb produces lesser light and shows higher temperatures on the thermometer. This shows that the incandescent bulb is less energy efficient. Most of the energy supplied to it as electricity is lost as heat. The florescent bulb on the other hand produces less heat and more light. This proves that the florescent one is more energy efficient.

# Fading Dot Experiment

### Aim:

The aim of this kid’s science fair project is to prove that there is a tiny jittering movement for our eyeballs with the help of the fading dot experiment.

### Materials required:

1.      A sheet of pink paper.

2.      A sheet of blue paper.

3.      A sheet of wax paper in order to cover the pink paper.

4.      A pair of scissors and glue.

### Procedure:

1.      Using scissors cut a piece out of the blue paper sheet, round in shape with 1-inch diameter.

2.      Paste this circular piece on the pink sheet using glue.

3.      Cover the pink sheet with the waxed paper and look at the dot through the waxed paper.

4.      Raise the waxed paper gradually while keeping your eyes fixed on the dot. Soon the edge of the dot becomes blurred and appears to mix with the field of pink.

5.      Now set your sight on a dot next to the blue dot. The blue dot will soon disappear.

### Scientific explanation:

This is because your eyes are constantly making tiny jittery movements involuntarily (you cannot stop it). The movement results in the eye capturing new images and sending the same to the brain. The same happens here as our eyes make the twitchy movements and the colour change at the edge of the dot is so slow that the eyes can’t make out the difference between a point on the dot and a neighbouring point. Thus when your eyes get no new information, the blue dot vanishes. But if there is a border circling the blue dot, the eyes can easily make it out and you will continue to see it.