Order of resistance for aluminium, mercury, copper,tungsten.

Options

A. R_Cu al w_hg
B. R_w hg al_cu
C. R_Cu hg al_w
D. R_al gt R_Hg

Answer

To determine the correct order of resistivity for aluminium, mercury, copper, and tungsten, we will follow these steps:

### Step 1: Understand Resistivity
Resistivity (\( \rho \)) is a property of a material that quantifies how strongly it resists the flow of electric current. The lower the resistivity, the better the material conducts electricity.

### Step 2: Gather Resistivity Values
We need to know the resistivity values for each of the materials:
- **Copper (Cu)**: \( \rho = 1.724 \times 10^{-8} \, \Omega \cdot m \)
- **Aluminium (Al)**: \( \rho = 2.65 \times 10^{-8} \, \Omega \cdot m \)
- **Tungsten (W)**: \( \rho = 5.65 \times 10^{-8} \, \Omega \cdot m \)
- **Mercury (Hg)**: \( \rho = 98 \times 10^{-8} \, \Omega \cdot m \)

### Step 3: Compare the Resistivity Values
Now, we will compare these values to determine their order from lowest to highest resistivity:
- Copper: \( 1.724 \times 10^{-8} \)
- Aluminium: \( 2.65 \times 10^{-8} \)
- Tungsten: \( 5.65 \times 10^{-8} \)
- Mercury: \( 98 \times 10^{-8} \)

### Step 4: Arrange in Order
From the values above, we can arrange the materials in order of increasing resistivity:
1. Copper (\( 1.724 \times 10^{-8} \))
2. Aluminium (\( 2.65 \times 10^{-8} \))
3. Tungsten (\( 5.65 \times 10^{-8} \))
4. Mercury (\( 98 \times 10^{-8} \))

### Final Order of Resistivity
Thus, the correct order of resistivity from lowest to highest is:
**Copper < Aluminium < Tungsten < Mercury**