Advertisements
Advertisements
प्रश्न
A diverging lens has a focal length of 0.10 m. The power of this lens will be:
विकल्प
+10.0D
+1.0D
−1.0D
−10.0D
Advertisements
उत्तर
10.0D,
since power of lens=`1/"focal length"=1/-0.10=-10.0D`
APPEARS IN
संबंधित प्रश्न
Define the power of a lens.
Find the power of a concave lens of focal length 2m.
Ranbir claims to have obtained an image twice the size of the object with a concave lens. Is he correct? Give a reason for your answer.
Name the physical quantity whose unit is dioptre.
Which type of lens has (a) a positive power, and (b) a negative power?
A convex lens of power 5 D and a concave lens of power 7.5 D are placed in contact with each other. What is the :
(a) power of this combination of lenses?
(b) focal length of this combination of lenses?
Two lenses A and B have focal lengths of +20 cm and, −10 cm, respectively.
(a) What is the nature of lens A and lens B?
(b) What is the power of lens A and lens B?
(c) What is the power of combination if lenses A and B are held close together?
What do you understand by the power of a lens? Name one factor on which the power of a lens depends.
State the condition for the following a ray passes undeviated through the lens .
How is the power of a lens related to its focal length?
Name the type of lens whose power is positive.
The image of an object formed by a lens is real, inverted and of the same size as the object. If the image is at a distance of 40 cm from the lens, what is the nature and power of the lens ? Draw ray diagram to justify your answer.
How does focal length of a lens change when red light incident on it is replaced by violet light? Give reason for your answer.
Complete the diagram to show the formation of the image of the object AB.
(i) Name the Lens LL’.
(ii) Where is the image of the object AB formed?
(iii) State three characteristics of the image.
If the lens is of focal length 25 cm. Calculate the power of the lens.
Focal length : metre : : power of lens : _______
The power of the magnifying glass depends on the distance of the magnifying glass from object.
If focal length of a convex lens is 20 cm at what is the power of the lens?
Power of a lens is – 4D, then its focal length is
The focal length of a double convex lens is equal to the radius of curvature of either surface. What is the refractive index of its material?
In what unit is the power of a lens expressed?
