# To measure the resistance of a current, flowing through different lengths of Nichrome Wires

Science Coursework                Andrew Robson

Resistance

Aim: To measure the resistance of a current, flowing through different lengths of Nichrome Wires

Prediction: I Predict that a shorter wire will have less resistance than a longer piece of the same substance.

Resistance is the property of any object or substance of resisting or opposing the flow of an electrical current. The quantity of resistance in an electric circuit determines the amount of current flowing in the circuit for any given voltage applied to the circuit. The unit of resistance is the ohm, the amount of resistance that limits the passage of current to one ampere when a voltage of one volt is applied to it. The standard abbreviation for electric resistance is R and the symbol for ohms in electric circuits is the Greek letter omega,   .

The resistance of an object is determined by a property of the substance of which it is composed, known as the resistivity, and by the length and cross-sectional area of the object, and by the temperature. At a given temperature, the resistance is proportional to the object's resistivity and length, and inversely proportional to its cross-sectional area. Usually, a material's resistance increases with increases in temperature.

Some Electronic circuits are varied in resistance using variable resistors (rheostat). These are used in lighting circuits (dimmer switches) and hi-fi systems (volume control) to vary the current flow. I will use one in my experiment because without one the amperes are too high and the reading goes of the scale

Factors Affecting Resistance

Length

Cross-Sectional Area

Materials – The atom structure is different so it easier for electrons to move is some the others.

Temperature

OHM'S LAW
Current flows ...