Quick Answer: What Is The Use Of Resistance In Electricity?

What are the 4 factors that affect resistance?

There are 4 different factors which affect resistance:The type of material of which the resistor is made.The length of the resistor.The thickness of the resistor.The temperature of the conductor..

What is resistance and its types?

All modern fixed value resistors can be classified into four broad groups: Carbon Composition Resistor – Made of carbon dust or graphite paste, low wattage values. Film or Cermet Resistor – Made from conductive metal oxide paste, very low wattage values.

What is electrical resistance and its unit?

Siemens per meterElectrical conductivityOhm meterElectrical resistivityElectrical resistance/SI units

What causes resistance?

An electric current flows when electrons move through a conductor, such as a metal wire. The moving electrons can collide with the ions in the metal. This makes it more difficult for the current to flow, and causes resistance.

What is the meaning of resistance?

1a : an act or instance of resisting : opposition. b : a means of resisting. 2 : the power or capacity to resist: such as. a : the inherent ability of an organism to resist harmful influences (such as disease, toxic agents, or infection)

What does high electrical resistance mean?

High electrical resistance is the opposition to current flow within a circuit. … A high electrical resistance of an electrical conductor is the opposition to the flow of an electric current through that conductor; the inverse measure is known as electrical conductance. The SI unit of electrical resistance is the ohm (O).

What is the relation between current and resistance?

The relationship between current, voltage and resistance is expressed by Ohm’s Law. This states that the current flowing in a circuit is directly proportional to the applied voltage and inversely proportional to the resistance of the circuit, provided the temperature remains constant.

Does resistance depend on power?

Power and Resistance Relation When power is high, resistance will be low. When power is low, the resistance will be high.

Why is resistance necessary in a circuit?

Resistance causes some of the electrical energy to turn into heat so some electrical energy is lost along the way. … Therefore, it is sometimes useful to add components called resistors into an electrical circuit to restrict the flow of electricity and protect the components in the circuit.

Is electrical resistance Good or bad?

Resistance can be helpful or just a drain on electrical energy. If the aim is to transmit electric current through a wire from one place to another, then resistance is a drawback. It reduces the amount of electrical energy that is transmitted because some of the current is absorbed by particles of matter.

What is the power of resistance?

The power dissipated in a resistor is given by P = V2/R which means power decreases if resistance increases. Yet this power is also given by P = I2R, which means power increases if resistance increases.

How do I calculate resistance?

If you know the total current and the voltage across the whole circuit, you can find the total resistance using Ohm’s Law: R = V / I. For example, a parallel circuit has a voltage of 9 volts and total current of 3 amps. The total resistance RT = 9 volts / 3 amps = 3 Ω.

What happens if resistance is too high?

If resistance is too high, current will be low if voltage is okay. NOTE: When the voltage stays the same, such as in an Automotive Circuit… current goes up as resistance goes down, and current goes down as resistance goes up. Bypassed devices reduce resistance, causing high current.

Why is resistance directly proportional to length?

As the length increases, the number of collisions by the moving free electrons with the fixed positive ions increases as more number of fixed positive ions are present in an increased length of the conductor. As a result, resistance increases.