Ohm's Law And Nichrome: Understanding The Relationship

Ohm's Law states that the potential difference between the two ends of a resistor is directly proportional to the current flowing through it. Nichrome is an alloy of nickel and chromium that has a constant resistance, meaning it shows a linear relationship between voltage and current. This is why nichrome is considered an ohmic or linear conductor and obeys Ohm's Law.

Nichrome's resistance remains constant over a wide temperature range

Nichrome is an alloy of nickel and chromium, and sometimes iron. It is used in electric heating elements, such as toasters and electric stoves, as well as in resistors.

Nichrome is designed to retain a constant resistance over a wide range of temperatures. This means that, when plotting current against voltage, it produces a straight-line graph, indicating that the ratio of voltage to current remains constant for variations in voltage. This is a key characteristic of Ohm's Law, which states that the potential difference between the two ends of a resistor is directly proportional to the current flowing through it.

Nichrome's resistance remains constant because it has a relatively stable resistance with temperature variation. Nichrome has a temperature coefficient of resistance per degree Celsius of 0.015%, compared to 0.4% for copper and 0.6% for iron. This means that, unlike other materials, nichrome's resistance does not change significantly as it heats up.

Nichrome's constant resistance over a wide temperature range makes it a useful material for applications where a stable resistance is required, such as in heating elements and resistors.

Nichrome is an alloy of nickel and chromium

Nichrome's resistance remains constant even when current and voltage change. This is because nichrome has a high resistance and a relatively stable resistance with temperature variation. Its resistance when cold is about 15 Ω, and when connected to 120 VAC, it glows red, demonstrating the heat produced when current flows through an element with high electrical resistance. When heated, nichrome develops an outer layer of chromium oxide, which is thermodynamically stable in air and protects the heating element from further oxidation.

Nichrome is also known for its high mechanical strength, high creep strength, and resistance to oxidation and the flow of electrons. These properties make it ideal for use in electric heating elements, such as in toasters, electric ranges, toaster ovens, percolators, drip coffee makers, and electric kettles.

Nichrome is considered 'ohmic' or 'linear'

Nichrome is an alloy of nickel and chromium, and sometimes iron. It is designed to retain a constant resistance over a wide range of temperatures. This means that, when plotting current against voltage, it produces a straight-line graph, and is therefore considered to be 'ohmic' or 'linear'.

Ohm's Law states that the temperature remaining constant, the current through a conductor is directly proportional to the voltage applied across the terminals of the conductor. In other words, the potential difference between the two ends of a resistor is directly proportional to the current flowing through it.

Nichrome's resistance does not change when current and voltage change. This means that it obeys Ohm's Law and is considered an ohmic conductor.

Nichrome is used in appliances such as toasters, electric ranges, toaster ovens, percolators, drip coffee makers, and electric kettles.

Nichrome's high resistance is why it heats up

Nichrome is an alloy composed of nickel, chromium, and, in some cases, iron. It has a high resistance and a high melting point of around 1400°C. This unique combination of properties makes nichrome wire ideal for use in heating appliances such as hair dryers, heat guns, and domestic heaters.

Nichrome's high resistance is due to its composition, which includes nickel, a metal known for its high electrical resistance. The alloy's resistance can be attributed to the presence of nickel, as well as the way the material opposes the flow of electric current. This property of opposing the flow of electricity is known as resistivity, and it is measured in ohm-meters (Ωm). The higher the resistivity, the stronger the material's opposition to the electric current. Nichrome's resistivity is approximately 1.10 × 10−6 Ωm to 1.50 × 10−6 Ωm, which is significantly higher than that of copper, which has a resistivity of 1.7 × 10−8 Ωm.

The high resistance of nichrome is further enhanced by its ability to retain a constant resistance over a wide range of temperatures. This characteristic makes nichrome an "ohmic" or "linear" material, meaning that when plotting current against voltage, it produces a straight-line graph. This linear relationship between voltage and current is a key characteristic of materials that obey Ohm's Law. Ohm's Law states that when the temperature remains constant, the current through a conductor is directly proportional to the voltage applied across its terminals.

The high resistance of nichrome is why it is commonly used in heating elements. When an electric current passes through a high-resistance material like nichrome, it encounters significant opposition, which causes the material to heat up. This process is known as Joule heating, and it is the principle behind how nichrome wires are able to convert electrical energy into heat energy in appliances such as toasters and ovens.

Nichrome is a good conductor of electricity

Ohm's Law states that the potential difference between the two ends of a resistor is directly proportional to the current flowing through it. In other words, when you place a potential difference across a resistor, a current flows through the resistor, and the magnitude of this current is linearly proportional to the potential difference and inversely proportional to the resistance of the resistor.

Nichrome is an alloy of nickel and chromium, and sometimes iron. It is a good conductor of electricity because it has a constant resistance, meaning it shows a linear relationship between voltage and current. This is despite the fact that nichrome has a high resistance. When plotting current against voltage, nichrome produces a straight-line graph, and so it is considered ''ohmic'' or 'linear'. Ohm's Law applies to nichrome because it obeys the rule that if you plot a graph of current against voltage and the result is a straight line, then the law applies.

Nichrome is used in electric heating elements because it has a low cost of manufacture, strength, ductility, resistance to oxidation, stability at high temperatures, and resistance to the flow of electrons. Nichrome wire glows red when connected to a power supply, showing the heat produced when current flows through an element that has electrical resistance. This is how appliances like toasters, electric ranges, percolators, and electric kettles work.

Nichrome is also used because it has a relatively stable resistance with temperature variation, it does not oxidise rapidly at high temperatures, it has a high melting point, and its high resistivity means that you can produce resistors of the required resistance and power ratings with relatively small amounts of wire.

Frequently asked questions