Advertisements
Advertisements
Question
State two advantages and two disadvantages of the reflecting periscope.
Advertisements
Solution
Advantages of Reflecting Periscope:
- It is used to see above the head of crowds.
- It is used by soldiers in trench warfare.
Disadvantages of Reflecting Periscope:
- The final images is not brightly illuminated as light energy is absorbed due to two successive reflections.
- Any deposition of moisture of dust on the mirror reduces the reflection almost to nil, and hence, the periscope cannot be used in places where there is a lot of dust or moisture.
APPEARS IN
RELATED QUESTIONS
State two uses of a plane mirror.
Draw a figure showing the following.
- Incident Ray
- Normal
- Angle of incidence
- Angle of reflection
- Point of incidence
- Reflected ray
Differentiate between the reflection of light from a plane mirror and that from a plane sheet of paper.
A light ray is incident normally on a plane mirror. What is the direction of reflected ray? Show it on a diagram.
Figure shows an incident ray AO and the normal ON on a plane mirror. The angle which the incident ray AO makes with mirror is 30°. (a) Find the angle of incidence. (b) Draw the reflected ray and then find the angle between the incident and reflected rays.
An object 3 cm high produces a real image 4.5 cm high when placed at a distance of 20 cm from a concave mirror. Calculate:
- the position of image
- focal length of the concave mirror.
Complete the path of incident ray in the following case.
______ through which light can pass completely.
