Arrange the following steps of an experiment in sequential order to calculate the focal length of a concave mirror when the object is at a small distance.
(A) Mount a concave mirror on the mirror stand and place an object in front of it at a certain distance.
(B) Adjust the position of the screen and the mirror until a bright and sharp image is obtained on the screen.
(C) Measure the distance between the object and the mirror. This distance gives the object distance u.
(D) Place the screen between the object and mirror but not in line with them.
(E) Measure the distance between the concave mirror and the screen. This gives the image distance v.
(F) The focal length of the given concave mirror can be found out using the mirror formula with proper signs.
(G) Repeat the experiment for different values of u and v and tabulate the results.

Options

A. A D B C E G F
B. A C E B D G F
C. A B C D E F G
D. A B D E C G E

Explanation

To calculate the focal length of a concave mirror when the object is at a small distance, we can arrange the steps of the experiment in the following sequential order:

1. **Step A**: Mount a concave mirror on the mirror stand and place an object in front of it at a certain distance.
- This is the initial setup where the concave mirror is fixed, and the object is positioned.

2. **Step D**: Place the screen between the object and mirror but not in line with them.
- The screen is positioned to capture the image formed by the mirror.

3. **Step B**: Adjust the position of the screen and the mirror until a bright and sharp image is obtained on the screen.
- Fine-tuning the positions ensures that a clear image is projected onto the screen.

4. **Step C**: Measure the distance between the object and the mirror. This distance gives the object distance \( u \).
- This measurement is crucial for calculating the focal length.

5. **Step E**: Measure the distance between the concave mirror and the screen. This gives the image distance \( v \).
- This step provides the necessary information to apply the mirror formula.

6. **Step F**: The focal length of the given concave mirror can be found out using the mirror formula with proper signs.
- The mirror formula \( \frac{1}{f} = \frac{1}{u} + \frac{1}{v} \) is applied here.

7. **Step G**: Repeat the experiment for different values of \( u \) and \( v \) and tabulate the results.
- This step involves conducting multiple trials to ensure accuracy and reliability of the results.

### Final Order of Steps:
- A → D → B → C → E → F → G