We are pleased to announce the Mousetrap Car Race. The race is one of the highlights of the High School Campus and it brings talented, creative minds together. In order to join the race, please follow the rules below.
Mixed Fruit Battery
A light bulb is connected in series with a coil of copper wire and a DC power supply. The voltage is adjusted so that the bulb glows dimly. When the coil is blown the temperature of the coil decreases. Thus, the resistance of the wire decreases causing the current to increase and the bulb to glow brightly.
Audio signals can be carried in radio waves through space and in electrical pulses through wires. Other forms of electromagnetic radiation, including visible light, can carry audio signals, too. You can build a simple device in which the signal from a radio is transmitted on a beam of light traveling between a light-emitting diode (LED) and a solar cell.
When the water at the bottom of the flask is heated, it expands. The expanded water is less dense than the surrounding water and therefore starts to rise. In doing so, the cooler regions of the water in the upper part of the flask, being denser, sink. This movement of the liquid due to a difference in its density sets up a convection current.
A light bulb is placed in series with two copper plates immersed in de-ionized water. Touching the plates closes the circuit, lighting the bulb.
When salt is dropped into the de-ionized water, the salt dissolves, causing ions to be dispersed throughout the liquid. The free ions allow current to flow through the water, which completes the circuit and lights the bulb.