Simple Generator

We slowly rotated the disc connected to the magnet to make a half turn. We also observed the two red light- emitting diodes and the voltmeter. After that, we rotated the disc fast to make a sudden half turn of the magnet.
When we turned the magnet slowly, the change of magnetic field is slow and little current is induced. When we quickly turned the magnet, the magnetic field changed rapidly making the LEDs light brightly. When we continuously turned the magnet at a faster rate, greater current is induced. The interval between the alternating current became so short that the LEDs light up and blinked continuously. This exhibit demonstrates generation of electricity.

Uphill Roller

The double cone rolls on a pair of wooden rails which are pitched slightly uphill as they widen. The cone seems to move uphill, because it rolls up the rails. It does so because as the rails widen, more of the cone falls below the level of the rails.

Van De Graaff generator

A Van de Graaff generator is an electrostatic generator which uses a moving belt to accumulate very high electrostatically stable voltages on a hollow metal globe on the top of the stand. Invented in 1929 by American physicist Robert J. Van de Graaff, the potential differences achieved in modern Van de Graaff generators can reach 5 megavolts. The Van de Graaff generator can be thought of as a constant-current source connected in parallel with a capacitor and a very large electrical resistance.

Some of the students tried this exhibit. Dearen, Mickay, Cham2x and Praicell were the students who tested the Van De Graaff generator.

Vibrating String

When we turned the knob clockwise, the string vibrated faster. Turning the knob counterclockwise causes the string to vibrate slowly.
The waves produced when the strings vibrated fast are shorter. Conversely, the waves produced by slow vibrating string are longer. The waves going out along the string and the reflected waves coming back combined to make a large motion of the string at some places and cancelled each other at the point called “nodes.”

Water Parabola

As the thin rectangular tank spins, the water in it tends to continue moving in a straight line tangent to the circle. However, the container restrains the water and forces it to keep moving in a circle. The water near the edge goes around in one large circle at the same time that the water near the center goes around in a small circle. This means that the water near the edge travels faster than the water near the center. The faster an object moves in a circle, the larger is the force necessary to hold it in the circle.

Wind Power

This exhibit showed how wind produces electricity. Cranking the blower fan generates enough air to move the turbine blades. The turbine is connected to the generator by means of a shaft. Inside the generator are magnets attached to the shaft. As the shaft rotated, electric current is induced in the coils of wire, making the LEDs light up.

Zoetrope

First, we looked through a slit on the disk and we saw a horse and its rider on the mirror. As we looked through the slit, we spanned the disk slowly and then spanned it faster again.
Painted on the side of the disc facing the mirror is a sequence of pictures of horses and riders. When we spanned the disk slowly, the horse and the rider seemed to move continuously like in a horse race.