What types of materials are used resistors?

Answer 1

Resistance: Electrical resistance describes how an electrical conductor (a wire) opposes the flow of an electrical current (flow of electrons). To overcome this opposition a voltage (a energy) must dropped (used) across the conductor (wire). Resistance can be described by ohms law: Ohms Law: R = V / I (Resistance = Voltage / Current) (resistance measured in ohms) where: Voltage [V]= the energy lost across an component (voltage measured in volts). Current [I] = the charge (electrons) flowing through an component (current measured in Amps). Electrical resistance can be thought of as sticking your hand out a car window. The faster [current] you drive the harder the wind presses [resistance] against you hand and therefore it takes more energy [voltage] to hold your steady. When trying to overcome electrical resistance, the electrical energy lost is turned into heat. This is how the elements of a household stove, toaster, and fan heater work. Because of the vacuum in a light bulb, the electrical energy lost is instead turned into light. It can be seen the electrical resistance plays a large role in modern life. Resistor: The resistor is the most common electronic component and is used to limit and/or control the voltage and current in an electronic circuit. Resistors are carefully manufactured to provide a predetermined value of electrical resistance which may range from 0.1 ohms to 100,000,000 ohms, depending on the application. The physical size of a resistor also varies dependant on the amount of power passing through the resistor, given by: P = V x I (Power = Voltage x Current) (power measured in watts) There are also many types of resistors including: · Variable Resistor - changes resistance when its shaft is rotated (volume knob on a stereo). · Thermistor - changes resistance when the temperature changes (used in a thermostat). · Light Dependant Resistor (LDR) - changes resistance when the lighting changes (used in children's night-lights). Resistor Example: An LED is a small red light (such as the one on the front of most TVs) and requires 2.0 volts and 0.02 amps to operate correctly. If we connected that LED up directly to a 12 volt battery, the voltage would be too high, and too much current would flow… the LED would blow up. We need to use a resistor to limit the voltage and current. But which value of resistance should the have resistor? Uses ohms law: R = V / I = (12.0 - 2.0) / 0.02 = 500 ohms (Note: the voltage across the resistor is the battery voltage minus the voltage we want across the LED) But which value of power should the resistor be capable of handling? P = V x I = (12.0 - 2.0) / 0.02 = 0.2 Watts hope this helps

Answer 2

Good resistors should have properties of adjustable electrical resistance, such as slide rheostat, resistance box.

The resistance of slide rheostat can be capable of continuous alteration, this is a good characteristic for slide rheostat. But we can not measure the definite number of the slide rheostat resistance.

For resistance box, we can read the exact numerical value of its resistance. Nervertheless, its resistance is discontinuous.

Answer 3

Is this question asking about the best conductor of heator the best conductor of electricity?

Copper is the best conductor of heat and electricity for most ordinary household and industrial purposes and it is much cheaper to buy than either silver or gold.

For extreme conditions - such as military or scientific applications - gold is the best conductor of electricity and liquid sodium is the best conductor of heat, but they are very expensive to buy and to put into use.

Answer 4

Here are examples of resistors:

filament in a bulb

wire

paper clip

what is an example of a resistor

Resistance reduces the flow of current in a conductor.

Resistors are devices that deliberately use this action, in a controlled and measured amount.

The unit of resistance is 'Ohms'

Fixed resistors come in varying physical sizes depending on the amount of current they are designed to handle.

Wire wound resistors, have a nichrome wire wrapped around a porcelain body, for large currents.

carbon resistors, made of carbon which is a poorer conductor than say copper.

Semi conductor, made of silicone and doped to reduce the conductivity.

variable resistor, comprises a track made of a resistance material, a wiper can then slide along the track and pick off a variable resistance compared to either end of the track.

Answer 5

Tree, Rubber The smaller and longer the better

Answer 6

Silver (yes, the precious stuff with the symble Ag)

Answer 7

some examples are outlets and extention cords