Resistance Flashcards
Conducting wire
Metal, power source and complete circuit, electrons to positive terminal
Resistance
Opposes passage of electrons, measured in ohms
Resistor
Electrical component which adds resistance to a circuit
Electrons moving through conductor
Collide with particles of which conductor is made, transfer kinetic energy, resistance, heats up
Uses of resistors
- control current
* useful energy transfers
Kettle
Metal coil, heating element, large resistor, electrons move through resistor, release energy, electrical to heat
Incandescent
- filament
- lights up
- inneficient
Light bulb
Filament, tungsten, high resistance, electrical to light
Rheostats
- variable resistance
- adjust current
- dimmer switches, speed of motors
Resistance works according to
Inverse proportion
LED
- light emitting diode
- one direction
- sensitive , large resistor
Factors that affect resistance
- material
- length
- thickness
- temp.
In metals electrons are
Able to move freely, delocalised