Write the ascending order of the units of length given below .
(a) Fermi `" "` (b) Micron
(c) Angstrom `" "` (d) Nanometre

Options

A. a,b,d,c
B. a,c,d,b
C. a,c,b,d
D. a,b,c,d

Answer

To arrange the given units of length in ascending order, we need to convert each unit into meters and then compare their values. Here’s the step-by-step solution:

### Step 1: Identify the values of each unit in meters
- **Fermi (fm)**:
- \(1 \, \text{Fermi} = 10^{-15} \, \text{meters}\)

- **Micron (µm)**:
- \(1 \, \text{Micron} = 10^{-6} \, \text{meters}\)

- **Angstrom (Å)**:
- \(1 \, \text{Angstrom} = 10^{-10} \, \text{meters}\)

- **Nanometre (nm)**:
- \(1 \, \text{Nanometre} = 10^{-9} \, \text{meters}\)

### Step 2: List the values in scientific notation
- Fermi: \(10^{-15}\)
- Angstrom: \(10^{-10}\)
- Nanometre: \(10^{-9}\)
- Micron: \(10^{-6}\)

### Step 3: Compare the values
Now, we can compare the powers of ten:
- \(10^{-15} < 10^{-10} < 10^{-9} < 10^{-6}\)

### Step 4: Write the units in ascending order
Based on the comparison, we can arrange the units from smallest to largest:
1. Fermi (fm)
2. Angstrom (Å)
3. Nanometre (nm)
4. Micron (µm)

### Final Answer
The ascending order of the units of length is:
**Fermi < Angstrom < Nanometre < Micron**

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