Do you travel in metros? When you reach the station you will see large spherical mirrors installed on the corners of the station. Do you know what type of mirror it is and why it is installed? It is a convex mirror. Convex mirror is a spherical mirror that is polished from the inside and outer surface is used for reflection. It gives a wide view to the observer. It is installed on the metro station so that when a train is stopped on the station the driver can view the whole train from inside the cabin. The convex mirror has such different uses. In this concept we will learn the various uses of convex mirrors.
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Convex mirrors are spherical mirrors having a painted inner surface and a reflecting outer surface. Convex mirror is also known as a diverging mirror. Because all rays striking on its surface appear to diverge from a single point. An image produced by a convex mirror is virtual because the center and focus of curvature are fictitious points inside the mirror and cannot be reached.
The convex mirror has following characteristics
Convex mirrors have a reflecting surface that extends outward in the direction of the light source. The extended surface reflects light in all directions and the image is created in the mirror. Consequently, it is impossible to project the image onto a screen. Convex mirrors are still useful in many aspects of daily life. Some of them are discuss below,
Q. What are the common uses of convex mirrors?
A. To provide a greater view of the entire area, convex mirrors are typically mounted in the halls of schools, apartments, hotels, and hospitals. Additionally, these spherical mirrors are utilized in driveways, alleyways, and roadways to give vehicles a wider perspective at intersections, curves, and other points where sight is poor.
Q. Explain the image formation by the convex mirror.
A. For forming an image of an object, draw a ray that is parallel to the principal axis. It will diverge in a direction as per the law of reflection. The ray pointed in the direction of the curvature's center will return in that same direction. Both the divergent rays will not meet after the reflection.If we extend these rays behind the mirror, A virtual and decreased image will form between the pole and the mirror's focus as shown in the figure.
Q. What are the general uses of concave mirrors?
A. Light reflected by concave mirrors focused inward to a point. As a result, they primarily serve to focus light. Depending on how close an object is to the concave mirror, multiple kinds of images appear. The concave mirror can be used in following purposes such as Shaving mirrors, Ophthalmoscope, Astronomical telescopes, Headlights, Solar furnaces.
Q. What are the laws of reflection? Is it applicable to convex mirrors?
A. Laws of reflection are applied for all mirrors including convex mirrors. According to the law of reflection the angle of incidence is equal to the angle of reflection and the incident ray, reflected ray and the normal to the surface are in the same plane.
Q. What kind of visual field does a convex mirror have?
A. This concave mirror has a wider range of view than a regular plane mirror because everything seems smaller in it.
Q. Why are convex mirrors used in cars?
A. Car rear-view mirrors are made of convex glass because of the larger field of view provided by these rearview mirrors which enables the drivers to see the traffic in their rearview mirror.
Q. Convex mirror forms real images true or false?
A. False. Convex mirror never forms real images; it always forms virtual, diminished and erect images.
Q. Why do blind turns employ convex mirrors?
A. Convex mirrors are used to protect drivers on highways and in streets where there is a blind spot or when there is little view for the driver.