Nichrome wire because it is made up of alloy and have high resistivity.

The correct answer for the material of heating element in electric heating appliances is option 'B', which is Nichrome. Let's understand why Nichrome is used as the heating element in electric appliances.

What is a heating element?
A heating element is a component in an electrical appliance that converts electrical energy into heat. It is responsible for generating the necessary heat required for various applications such as heating water, cooking food, or drying clothes.

Properties of a heating element:
A heating element should possess certain properties to be suitable for its application. These properties include:

1. High resistance: The material should have a high resistance to allow the flow of current, which in turn generates heat.
2. High melting point: The material should have a high melting point to withstand the high temperatures generated during operation.
3. Good oxidation resistance: The material should be able to resist oxidation or corrosion at high temperatures.
4. Low temperature coefficient of resistance: The resistance of the material should not change significantly with temperature variations.

Why is Nichrome used as a heating element?
Nichrome, an alloy of nickel and chromium, meets the above-mentioned properties required for a heating element. Here's why Nichrome is a preferred choice:

1. High resistance: Nichrome has a high resistivity, which means it has a high resistance to the flow of electric current. This property allows it to generate a significant amount of heat when an electric current passes through it.
2. High melting point: Nichrome has a high melting point of around 1400°C, making it suitable for applications that require high temperatures, such as heating appliances.
3. Good oxidation resistance: Nichrome forms a protective oxide layer when exposed to air, which prevents further oxidation. This property helps in preventing the material from deteriorating or breaking down due to oxidation at high temperatures.
4. Low temperature coefficient of resistance: Nichrome has a relatively low temperature coefficient of resistance, meaning its resistance does not change significantly with temperature variations. This ensures that the heating element remains stable and consistent in its performance.

Other materials:
While Nichrome is commonly used as a heating element material, other materials such as brass, silver, and copper have different properties that make them unsuitable for this purpose. Brass and copper have relatively low resistivity, which means they would not generate as much heat as required. Silver, on the other hand, has a high cost and is less commonly used due to its expense.

In conclusion, Nichrome is the preferred material for heating elements in electric appliances due to its high resistance, high melting point, good oxidation resistance, and low temperature coefficient of resistance. These properties make it an efficient and reliable choice for generating heat in various heating applications.