Geometrical Optics

Question 1

What is a lens ?

Answer 1

A piece of Transparent material that can focus a transmitted beam of light

Question 2

What are two types of lenses ?

Answer 2

🥱convex / converging lens

🥱 diverging/ concave lens

Question 3

The point f to which the rays are brought to focus is called?

Answer 3

Principal focus or focal point

Question 4

Distance between optical centre and its principle focus is called

Answer 4

Focal length

Question 5

Convex lens gives

Answer 5

Real image

Question 6

Concave gives

Answer 6

Virtual images

Question 7

Real Images are always ?

Answer 7

Inverted

Question 8

Virtual images are always ?

Answer 8

Errect

Question 9

What is Visual angle ?

Answer 9

The apparent size of the object depends upon angle substanted by the eye

Question 10

Least distance of distinct vision is?

Answer 10

25cm

Question 11

A type of convex lens which brings object closer is called ?

Answer 11

Magnifying 🔍 glass

Question 12

An optical instrument which is used to see small object with very high magnification is called ?

Answer 12

Compound microscope 🔬

Question 13

Image formed by compound microscope is ?

Answer 13

Virtual and very much magnified

Question 14

Optical instrument used to see distant object and heavenly bodies that is planets and stars is called ?

Answer 14

Astronomical telescope

Question 15

Image formed by astronomical telescope is ?

Answer 15

Highly magnified / inverted / virtual

Question 16

Distance between objective and eye piece 🧩 is called ?

Answer 16

Length of telescope 🔭

Question 17

An instrument used to see objects on earth is called

Answer 17

Galilean Telescope

Question 18

Instrument which is used to study the spectrum of luminous bodies is called?

Answer 18

Spectrometer

Question 19

The front of eye is covered by transparent membrane called?

Answer 19

Cornea

Question 20

Muscular diaphragm that control the size of pupil ?

Answer 20

Iris

Question 21

When images formed behind retina … The Abnormality is ?

Answer 21

✓ Myopia ( far sighted )

✓corrected by using converging lens

Question 22

When image is formed Infront of retina … The Abnormality is known as ?

Answer 22

✓Hyperopia or short sightedness

✓ corrected by using diverging lens

Question 23

Bright sunlight is an example of ?

Answer 23

Convex lens

Question 24

When the magnification of a lens is less than 1 , it means the image is actually :

Answer 24

M(Dec) q (Dec )

Smaller than obj

Question 25

Smaller the distance of object from the eye 👁️ the visual angle will be ?

Answer 25

Visual angle ( inc ) distance (Dec)

Greater

Question 26

Linear magnification produced by a lens is defined as :

Answer 26

The ratio of size of image to size of object