Angular magnification of telescope if focal length of objective and eye lenses are 10 cm and 10 mm respectively and tube length is 11cm:

Options

A. 10
B. 5
C. 100
D. 50

Explanation

To find the angular magnification of the telescope, we will follow these steps:

### Step 1: Identify the given values
- Focal length of the objective lens, \( f_o = 10 \, \text{cm} \)
- Focal length of the eye lens, \( f_e = 10 \, \text{mm} \)
- Tube length, \( L = 11 \, \text{cm} \)

### Step 2: Convert all measurements to the same unit
Since the focal length of the eye lens is given in millimeters, we convert it to centimeters for consistency:
\[ f_e = 10 \, \text{mm} = 1 \, \text{cm} \]

### Step 3: Use the formula for angular magnification
The angular magnification \( M \) of a telescope is given by the formula:
\[ M = \frac{f_o}{f_e} \]

### Step 4: Substitute the values into the formula
Now, substituting the values we have:
\[ M = \frac{f_o}{f_e} = \frac{10 \, \text{cm}}{1 \, \text{cm}} = 10 \]

### Step 5: State the result
The angular magnification of the telescope is:
\[ M = 10 \]

### Conclusion
Thus, the angular magnification of the telescope is 10 (unitless).

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