Advertisements
Advertisements
प्रश्न
Advertisements
उत्तर
Focal length (in metres) = `1/"power(in dioptres)"`
Focal length (in metres) = `1/2` = 0.5m = 50 cm
Since, the focal length is positive, the lens is aconvex lens.
APPEARS IN
संबंधित प्रश्न
What is a lens?
In figure, (a) and (b), F1 and F2 are the two foci of thin lenses and AB is the incident ray. Complete the diagram to show the path of the ray AB after refraction through each lens.
 |
| (a) |
 |
| (b) |
A ray of light incident parallel to the principal axis of a lens, passes undeviated after refraction.
What type of lenses are used in spectacles worn by an old lady for knitting?
Make the correct choices in the following items :
A lens used as a magnifying glass
(i) ls a diverging lens
(ii) Produces a virtual image
(iii) ls placed with the object nearer the lens than the principle focus
Make the correct choices in the following items :
The image formed by a diverging lens, shown in fig, , is
Name the subjective property of light related to its wavelength.
The diagram showed a lens as a combination of one glass block and two prisms. Complete the ray diagram and show the part of the incident ray AB after passing through the lens.
(i) Name of the lens formed by the combination.
(ii) What is the line XX’ called?
(iii) Mark the focus F.
Complete the following diagram and state what happens to the ray of light after refraction through the lens.
Mixture of red + blue + green is passed through a convex lens as shown in the diagram below. State whether the ray passes through a single point or through different points on the principal axis after refraction.
