an electric fuse is a safety device which protects the circuit n electrical appliances from damage due to high electricity...when rated current flows in the wire the fuse remains connected but if current more than the rated current flows the heat produced in the fuse wire is enough to melt it .....therfore we should not use fuse other than the rated fuse

Role of Fuse in Series with Electrical Appliance in an Electric Circuit

A fuse is an important safety device that is used to protect electrical circuits and appliances from damage caused by excessive current. It is typically a small, cylindrical object that is placed in series with an electrical appliance in an electric circuit.

1. Protection against Overcurrent
The primary role of a fuse is to protect the electrical appliance and the circuit from overcurrent. When the current flowing through the circuit exceeds the rated value of the fuse, the fuse wire or element inside the fuse melts, thereby breaking the circuit and stopping the flow of current. This prevents the electrical appliance from getting damaged due to excessive current.

2. Preventing Electrical Fires
Fuses also play a crucial role in preventing electrical fires. In case of a short circuit or a fault in the electrical appliance, a large amount of current can flow through the circuit. This can generate excessive heat, potentially leading to fire hazards. By breaking the circuit when the current exceeds the rated value, the fuse helps to prevent such dangerous situations.

3. Protecting Electrical Components
Electrical appliances consist of various components, such as motors, transformers, and sensitive electronic circuits. These components have their own current ratings, and excessive current can cause damage to them. By interrupting the flow of current when it exceeds the rated value, the fuse protects these components from potential harm.

Why a Fuse with Defined Rating Should Not be Replaced by a Larger Rating?

It is crucial to use a fuse with the defined rating specified for the electric circuit. Replacing it with a fuse of a larger rating can have several negative consequences:

1. Compromised Safety
Using a fuse with a larger rating than recommended bypasses the safety measures put in place. The fuse is designed to break the circuit and protect against overcurrent. By replacing it with a higher-rated fuse, the circuit may not break even when excessive current flows, increasing the risk of damage to the appliance and potential fire hazards.

2. Damage to Electrical Components
Electrical appliances are designed to operate within certain current limits. Using a fuse with a higher rating can allow the flow of excessive current, which can damage the electrical components of the appliance. This can lead to costly repairs or even render the appliance irreparable.

3. Overloading the Circuit
Circuits are designed to handle a specific amount of current. Using a higher-rated fuse increases the current-carrying capacity of the circuit beyond its intended limits. This can lead to overloading the circuit, causing overheating and potential damage to the wiring, switches, and other components of the circuit.

In conclusion, a fuse plays a critical role in protecting electrical appliances and circuits from overcurrent and potential damage. It is essential to use a fuse with the defined rating to ensure safety, prevent damage to electrical components, and avoid overloading the circuit. Replacing a fuse with a larger rating compromises these safety measures and can lead to hazardous situations.