What is a Resistance

TL;DR

Resistance is a property of a material that opposes the flow of current in an electrical circuit.

Transcript

hello friends in this video we are going to study that what is a resistance how we can define it and what are the ways in which the resistance can be expressed and what are the factors on which the resistance depends so let us start with our topic resistance is the property of a material which opposes the flow of current through the conductor okay ... Read More

Key Insights

• 💐 Resistance is a property of a material that opposes current flow in an electrical circuit.
• ❓ Ohm's Law is used to calculate resistance when the temperature is constant.
• ❓ When the temperature is not constant, the resistance can be calculated using a formula involving the initial and final temperatures.
• 😑 The resistance of a material can also be expressed in terms of its physical dimensions using the formula R = ρl/A.
• 😘 Properties such as stability, low temperature coefficient of resistance, high resistivity, and resistance to oxidation, corrosion, and moisture are desirable for a good resistor.
• 🇦🇪 The unit of measurement for resistance is ohms.
• 📣 Resistance can vary from a few ohms to several mega ohms.

Questions & Answers

Q: What is resistance in an electrical circuit?

Resistance is the property of a material that opposes the flow of current in an electrical circuit. It is measured in ohms.

Q: How is resistance calculated using Ohm's Law?

Ohm's Law states that resistance (R) is equal to voltage (V) divided by current (I). So, R = V/I.

Q: How can resistance be calculated when the temperature is not constant?

When the temperature is not constant, resistance can be calculated using the formula R2 = R1(1 + α(T2 - T1)), where R1 is the initial resistance, T1 is the initial temperature, T2 is the final temperature, and α is the temperature coefficient of the material.

Q: What is the formula for resistance in terms of the physical dimensions of the material?

The formula for resistance in terms of the physical dimensions is R = ρl/A, where ρ is the resistivity, l is the length of the material, and A is the cross-sectional area.

Summary & Key Takeaways

• Resistance is the property of a material that hinders the flow of current in an electrical circuit.

• It can be measured using Ohm's Law, where resistance (R) is equal to voltage (V) divided by current (I).

• Resistance can also be calculated using the formula R = ρl/A, where ρ is the resistivity, l is the length of the material, and A is the cross-sectional area.