### Shortcut Methods

**Numerical Values for Reflection of Light and Formation of Images**

**1. Mirror Formula (for spherical mirrors)**:

- Object distance (u): Typically ranges from a few centimeters to infinity (∞).
- Image distance (v): Can be positive (for real images) or negative (for virtual images).
- Focal length (f): Typically ranges from a few centimeters to a few meters.

**2. Magnification (for spherical mirrors)**:

- Lateral magnification (m): Can be positive (enlarged image) or negative (diminished image).
- Values for lateral magnification can range from less than 1 (diminished image) to greater than 1 (enlarged image).

**3. Mirror Equation:**

- Relation between object distance (u), image distance (v), and focal length (f) is given by
**1/u + 1/v = 1/f**.

**4. Laws of Reflection:**

- Angles of incidence (i) and reflection (r) are typically measured in degrees and their values are equal, i.e.,
**i = r**.

**5. Ray Tracing Diagrams:**

- Construction of ray diagrams for spherical mirrors involves drawing incident rays parallel to the principal axis, rays through the center of curvature, and rays toward the focus.

**6. Sign Conventions:**

- Standard sign conventions are used for distances and heights:
- Distances are positive for real objects and negative for virtual objects.
- Heights are positive for images above the principal axis and negative for images below the principal axis.

**7. Focal Length Measurements:**

- The focal length of a spherical mirror can be experimentally determined using the object-image distance relationship or the thin lens equation.

**8. Types of Images:**

- Real images are formed by the actual convergence of reflected light rays, while virtual images appear to form behind the mirror due to the divergence of reflected rays.

**Note**:

These numerical values are approximate and can vary depending on the specific problem or scenario.