The resistance of the fuse wire is

Options

A. low
B. moderate
C. zero
D. very high

Answer

To determine the resistance of a fuse wire, we need to consider its purpose and characteristics. Here’s a step-by-step solution:

### Step 1: Understand the Purpose of a Fuse Wire
A fuse wire is designed to protect electrical circuits by breaking the circuit when the current exceeds a certain level. This prevents damage to appliances and reduces the risk of fire.

**Hint:** Remember that the main function of a fuse is to act as a safety device.

### Step 2: Analyze the Relationship Between Resistance and Current
When a high current flows through the fuse wire, it generates heat due to the resistance of the wire. If the resistance is too low, the wire will not heat up sufficiently to melt and break the circuit.

**Hint:** Think about how resistance affects current flow and heat generation.

### Step 3: Determine the Required Resistance
For the fuse to operate effectively, it must have a high resistance. A high resistance allows for significant heat generation when high current flows, leading to the melting of the wire.

**Hint:** Consider what happens to a wire with low resistance when a high current passes through it.

### Step 4: Evaluate the Options Given
The options provided are low, moderate, zero, and very high resistance. Since we established that the fuse wire needs to generate enough heat to melt and break the circuit, the correct choice must be high resistance.

**Hint:** Eliminate the options that do not meet the criteria for effective operation of a fuse.

### Step 5: Conclusion
The resistance of the fuse wire is **very high**. This high resistance is crucial for the fuse to function properly and protect the circuit from overcurrent.

**Final Answer:** The resistance of the fuse wire is very high.