My PBL Project

Procedure-

First you will crank the generator with the light bulb and create light. Then you will connect the two generators and crank one handle and the other handle should begin to turn slowly. You will count how many turns you need to make to make one full turn on the opposite crank.

Scientific principle-

Conductive wire through a magnetic field produces an electric current in the wire, thus creating electricity.

The science in the hand cranked generator is AC and DC currents. The direct current and the Alternative current. A direct current is when you turn the handle one way and it creates the electricity. But the Alternative current is when the direction in which you are moving the handle changes rapidly.

Electric generators convert mechanical energy to electrical energy; they induce an EMF by rotating a coil in a magnetic field.

electromotive force

(EMF)—The voltage generated by a battery or by the magnetic force according to Faraday's Law. It is measured in units of volts, not newtons, and thus, is not actually a force.

Flux

Flux is the rate of transfer of fluid, particles, across a given surface.

Efficiantcy

You can tell the efficiantcy of a hand cranked generator by connecting two generators and turning only one of the handles. When you turn the handle the handle on the other handle will begin to turn. Count how many turns it takes on the main generator to make one rotation on the second generator. This will calclate the efficiantcy.

Investigation

generator light brightness varies, if you turn the handle fast the light will be bright. If you turn the handle at a constant speed it will brighten and become dim and it will repeat. In my experience and in knowing about Faradays law, I believe that the coil and the magnet in the hand cranked generator would be placed surrounding the copper wire coil. The magnetic field around a current carrying wire is different from the coil and wires magnetic field because the coil and wire have no direct contact and a current carrying wire does. Also because the coil is surrounded by a magnet the magnetic field is much greater. Another thing I learned is why Faradays law has a negative sign, and it is because it expresses the conservation of energy.

Faraday's Law

Faraday's law says that when a magnet is moved towards or away from a coil of wire a change in voltage will be generated.

KEY POINTS

A hand crank generator rotates a coil in a magnetic field, inducing an emf given as a function of time.

Generators (Hand Crank) supply almost all of the power for the electric power grids which provide most of the world's electric power.

A motor becomes a generator when its shaft rotates.