Question 708 of 949
When light reflects off a concave mirror, which of the following statements is true regarding the image formed by the mirror when the object is placed beyond the center of curvature?
- The image is virtual, upright, and larger than the object.
- The image is real, inverted, and smaller than the object.
- The image is real, inverted, and larger than the object.
- The image is virtual, inverted, and the same size as the object.
Correct Answer:
C
Explanation
### Correct Option: C. The image is real, inverted, and larger than the object.
#### Step-by-Step Explanation:
1. **Understanding Concave Mirrors**:
- A concave mirror is a mirror that curves inward, resembling a portion of the interior of a sphere. It has a focal point (F) where parallel rays of light converge after reflecting off the mirror.
2. **Object Placement**:
- When we say the object is placed "beyond the center of curvature," we mean that the object is located at a distance greater than twice the focal length of the mirror (i.e., beyond the center of curvature, which is at a distance of 2F from the mirror).
3. **Ray Diagram**:
- To analyze the image formation, we can draw a ray diagram:
- **Ray 1**: A ray parallel to the principal axis strikes the mirror and reflects through the focal point (F).
- **Ray 2**: A ray passing through the focal point strikes the mirror and reflects parallel to the principal axis.
- **Ray 3**: A ray striking the mirror at its vertex reflects at the same angle relative to the principal axis.
- The intersection of these reflected rays indicates the location of the image.
4. **Image Characteristics**:
- When the object is beyond the center of curvature:
- The image formed is **real** because the reflected rays converge at a point.
- The image is **inverted** because the rays cross over after reflection.
- The image is **larger** than the object because the object is placed beyond 2F, leading to a magnification greater than 1.
5. **Mathematical Confirmation**:
- The mirror formula is given by:
\[
\frac{1}{f} = \frac{1}{d_o} + \frac{1}{d_i}
\]
where \( f \) is the focal length, \( d_o \) is the object distance, and \( d_i \) is the image distance.
- The magnification (M) can be calculated using:
\[
M = -\frac{d_i}{d_o}
\]
- Since \( d_o > 2f \), it can be shown that \( d_i \) will be positive and greater than \( d_o \), confirming that the image is real and larger.
#### Why Other Options Are Incorrect:
- **Option A**: The image is virtual, upright, and larger than the object.
- **Incorrect**: A concave mirror produces a virtual image only when the object is placed between the focal point and the mirror. In this case, the object is beyond the center of curvature, leading to a real image.
- **Option B**: The image is real, inverted, and smaller than the object.
- **Incorrect**: While the image is indeed real and inverted, it is not smaller; it is larger than the object when the object is beyond the center of curvature.
- **Option D**: The image is virtual, inverted, and the same size as the object.
- **Incorrect**: As mentioned, a virtual image is not formed in this scenario. The image is real and inverted, and it cannot be the same size as the object when the object is beyond the center of curvature.
### Revision Summary:
- A concave mirror produces a **real, inverted, and larger** image when the object is placed beyond the center of curvature.
- The image characteristics can be confirmed using ray diagrams and the mirror formula.
- Virtual images are only formed when the object is within the focal length of the mirror.
- Understanding the placement of the object relative to the focal point and center of curvature is crucial for predicting image characteristics.