Question

The fuse wire in electric circuit is made of

• A. Tin-lead alloy
• B. Copper
• C. Tungsten
• D. Nichrome

Hint:

Electrical Materials:
Fuse Wire = TIN-LEAD ALLOY (Low melting point $183^\circ\text{C}$).
Heating Element = Nichrome.
Lamp Filament = Tungsten.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Electrical circuit protection and fuse element metallurgy: standard electrical cartridge and rewirable fuse links are manufactured from a eutectic alloy of Tin and Lead (typically 63% Sn 37% Pb or 60/40 solder alloy) characterized by low melting point ($183-230^\circ ext{C}$), high conductivity, and non-deteriorating oxidation resistance.
Key Formula or Approach:
\[ \text{Fuse Joule Heating: } H = I^2 R t \quad \xrightarrow{I > I_{\text{rated}}} \quad \mathbf{\text{Tin-Lead Alloy Melting Point } (183^\circ\text{C}) \implies \text{Instant Circuit Interruption}} \]

Step 2: Detailed Explanation:
In electrical engineering, circuit protection, and power distribution in dairy plants:
- An electric fuse is a sacrificial protective device that interrupts excessive fault currents (short-circuits and severe overloads):
1. Material Requirements for Fuse Wire:
- Low melting point (to melt quickly before insulation burns).
- High electrical conductivity (low resistance under normal loads to minimize voltage drop).
- Freedom from rapid oxidation.
2. Tin-Lead Alloy (A): Standard fuse wires are fabricated from an alloy of Tin ($60\% - 63\%$) and Lead ($37\% - 40\%$), which melts at approximately $183^\circ - 230^\circ ext{C$}. When over-current flows, $I^2 R$ Joule heating rapidly melts the wire, opening the circuit safely.
3. (Copper is used for high-current HRC fuses; Tungsten is used for lamp filaments; Nichrome is used for heating elements).

Step 3: Final Answer:
Therefore, the fuse wire is made of Tin-lead alloy, corresponding to option (A).