Answer the following questions.
a. Explain the difference between a plane mirror, a concave mirror and a convex mirror with respect to the type and size of the images produced.
b. Describe the positions of the source of light with respect to a concave mirror in
1.Torch light
2. Projector lamp
3. Flood light
c. Why are concave mirrors used in solar devices?
d. Why are the mirrors fitted on the outside of cars convex?
e. Why does obtaining the image of the sun on a paper with the help of a concave mirror burn the paper?
f. If a spherical mirror breaks, what type of mirrors are the individual pieces?
a. Explain the difference between a plane mirror, a concave mirror and a convex mirror with respect to the type and size of the images produced.
1.Torch light
3. Flood light
a.
Mirror Type of image Size of image Plane mirror Virtual and erect Same size as that of object Concave mirror Real and inverted as well as virtual and erect depending on the position of object w.r.t. the mirror Magnified, diminished as well as same size as that of object depending on the position of object w.r.t. the mirror Convex mirror Always virtual and erect Always diminished
b.
1.Torch light: The source of light is placed at the focus of the mirror to obtain a parallel beam of light.
2. Projector lamp: The source of light is placed at the centre of curvature of the mirror.
3. Flood light: The source of light is placed just beyond the centre of curvature of the mirror to obtain bright beam of light.
c. Concave mirror is also known as converging mirror because of its ability of focus the parallel rays at a single point anywhere on its focal plane. This property of concave mirror is used in solar devices. Parallel rays from the Sun falling on the concave mirror of a solar device are focussed at the particular point to generate a lot of heat required for the proper functioning of the device.
d. Convex mirrors have the ability to cover wider field of view by forming diminished and virtual image of the objects. Thus, the mirrors fitted on the outside of cars are convex so that larger view of the road can be observed by the driver sitting in the car.
e. The rays from the Sun are parallel. When these rays fall on the concave mirror, they are converged to a single point on the focal plane of the mirror. Thus a lot of heat is produced at that point. Now, if a paper is placed at that point to get the image of the Sun, the paper gets burnt because of huge amount of heat concentrated at that point.
f. When spherical mirror breaks, their nature does not change. This means if a concave mirror breaks into pieces, the pieces will act as concave mirros only. Same happens in case of convex mirrors.
a.
| Mirror | Type of image | Size of image |
| Plane mirror | Virtual and erect | Same size as that of object |
| Concave mirror | Real and inverted as well as virtual and erect depending on the position of object w.r.t. the mirror | Magnified, diminished as well as same size as that of object depending on the position of object w.r.t. the mirror |
| Convex mirror | Always virtual and erect | Always diminished |
b.
1.Torch light: The source of light is placed at the focus of the mirror to obtain a parallel beam of light.
2. Projector lamp: The source of light is placed at the centre of curvature of the mirror.
3. Flood light: The source of light is placed just beyond the centre of curvature of the mirror to obtain bright beam of light.
c. Concave mirror is also known as converging mirror because of its ability of focus the parallel rays at a single point anywhere on its focal plane. This property of concave mirror is used in solar devices. Parallel rays from the Sun falling on the concave mirror of a solar device are focussed at the particular point to generate a lot of heat required for the proper functioning of the device.
d. Convex mirrors have the ability to cover wider field of view by forming diminished and virtual image of the objects. Thus, the mirrors fitted on the outside of cars are convex so that larger view of the road can be observed by the driver sitting in the car.
e. The rays from the Sun are parallel. When these rays fall on the concave mirror, they are converged to a single point on the focal plane of the mirror. Thus a lot of heat is produced at that point. Now, if a paper is placed at that point to get the image of the Sun, the paper gets burnt because of huge amount of heat concentrated at that point.
f. When spherical mirror breaks, their nature does not change. This means if a concave mirror breaks into pieces, the pieces will act as concave mirros only. Same happens in case of convex mirrors.
