Electricity

The range of the weak nuclear force is extremely short, on the order of 10⁻¹⁶ meters.

The material commonly used in electric heaters is nichrome.

Nichrome is an alloy typically composed of approximately 80% nickel and 20% chromium. It is preferred for heating elements due to its desirable properties:

1. High resistivity: This means it offers significant resistance to the flow of electric current, causing it to heat up considerably when current passes through it (Joule heating).
2. High melting point: Nichrome can withstand high temperatures without melting or deforming, which is crucial for heating applications.
3. Resistance to oxidation: It forms a protective layer of chromium oxide when heated in air, which prevents further oxidation and prolongs the life of the heating element.
4. Good mechanical strength: It is relatively strong and ductile, allowing it to be drawn into wires or formed into coils.

While other materials with high resistivity exist, nichrome offers a good balance of these properties, making it a cost-effective and reliable choice for electric heaters, toasters, hair dryers, and other heating appliances.

The filament of an electric bulb is made of tungsten.

Tungsten is used because it possesses several key properties that make it ideal for this application:

1. High melting point: Tungsten has the highest melting point of all metals (around 3410 °C or 6170 °F). This is crucial because the filament needs to withstand the high temperatures generated when electricity passes through it and makes it glow.
2. Low vapor pressure: At high operating temperatures, tungsten has a low rate of evaporation. This ensures that the filament doesn't thin out and burn away quickly, prolonging the bulb's life.
3. High tensile strength: Even at high temperatures, tungsten retains its strength, preventing the filament from breaking or deforming easily.
4. Good electrical resistivity: Tungsten has a relatively high electrical resistance, which causes it to heat up and glow intensely when an electric current flows through it.

While other materials were tried in the early days of light bulb development, tungsten proved to be the most suitable due to this unique combination of properties.

The filament of an electric bulb is made of tungsten.

Tungsten is used because it possesses several key properties that make it ideal for this application:

1. High melting point: Tungsten has the highest melting point of all metals (around 3410 °C or 6170 °F). This is crucial because the filament needs to withstand the high temperatures generated when electricity passes through it and makes it glow.
2. Low vapor pressure: At high operating temperatures, tungsten has a low rate of evaporation. This ensures that the filament doesn't thin out and burn away quickly, prolonging the bulb's life.
3. High tensile strength: Even at high temperatures, tungsten retains its strength, preventing the filament from breaking or deforming easily.
4. Good electrical resistivity: Tungsten has a relatively high electrical resistance, which causes it to heat up and glow intensely when an electric current flows through it.

While other materials were tried in the early days of light bulb development, tungsten proved to be the most suitable due to this unique combination of properties.

• When too much current flows through a circuit due to overloading or a short circuit, the fuse coil overheats and melts, causing the circuit to break and stop flowing.
• A fuse is always placed in an electric wire.
• It works on the principle of the thermal effect of electricity.

• A fuse is a piece of wire made of an alloy with a very low melting point.
• When the temperature of the wire rises due to overloading in an electric circuit, the fuse wire is already broken and the current stops.

• An electric fuse consists of a low melting point (rapidly melting) metal wire, which heats up and melts when a high current is passed, stopping current flow by breaking the circuit.