Lab:8 To determine the focal length of two lenses when they are separated by some finite distance

1. Theory

1.1 Lens combination formula derivation

1.2 Equivalent focal length concept

1.3 Mathematical relationship for separated lenses

2. Apparatus

2.1 Optical bench with uprights

2.2 Convex and concave lenses

2.3 Light source and screen

2.4 Lens holders and measuring scale

3. Procedure

3.1 Setup and alignment instructions

3.2 Method for finding individual focal lengths

3.3 Combination measurement technique

3.4 Image formation observations

4. Observations

4.1 Tabular data for single lens measurements

4.2 Combination lens position data

4.3 Multiple readings for accuracy

5. Calculations

5.1 Individual focal length calculations

5.2 Equivalent focal length derivation

5.3 Percentage error analysis

6. Results

6.1 Final calculated values

6.2 Comparison with theoretical values

6.3 Conclusion and error discussion

7. Precautions

7.1 Alignment considerations

7.2 Measurement accuracy tips

7.3 Common errors to avoid