Refraction Through Spherical Lens, Class 10 Science NCERT Solutions

1. There will be total 20 MCQ in this test.
2. Please keep a pen and paper ready for rough work but keep your books away.
3. The test will consist of only objective type multiple choice questions requiring students to mouse-click their correct choice of the options against the related question number.
4. No negative marking for incorrect choice.
5. Please click on “Finish the Test” when you want to exit.
6. All the best – Happy Studying

1. If a lens has a focal length, F = +12 cm, then it is a

Can be convex or concave

Convex lens

Diverging lens

Concave lens

Question 1 of 20

2. If a lens has a focal length, f = -12 cm. then it is a

Convex lens

Can be convex or concave

Concave lens

Question 2 of 20

3. Which lens always forms a virtual image?

Concave lens

Convex lens

Converging lens

Both convex and concave

Question 3 of 20

4. In a convex lens, where is the image formed, when an object is placed at 2F?

Between F and 2F

At focus (F)

At 2F on the same side

At 2F on the other side

Question 4 of 20

5. What happens to the image formed by a convex lens if its lower part is blackened?

Full image will form but intensity of image will be less

full image but of small size will be formed

upper part of image will be visible

lower part of image will be visible

Question 5 of 20

6. Which lens has a virtual focus?

Concave lens

Convex lens

Converging lens

Both convex and concave

Question 6 of 20

7. Which lens always forms diminished and erect image?

Convex lens

Concave lens

Converging lens

Both convex and concave

Question 7 of 20

8. A ray of light incident on the optical centre of a spherical lens, after refraction passes through:

Radius of curvature

Optical centre

Twice the focal length

Principal focus

Question 8 of 20

9. The focal length of a concave lens is:

always positive

positive when image formed is real

negative when image formed is real

always negative

Question 9 of 20

10. Four students A, B, C and D did their experiment on finding the focal length of convex lens by obtaining the image of a distant object as follows:
Student A used the window grill in the laboratory as the object and a white paper sheet held in hand, as the screen.
Student B used a distant tree in absence of sunlight as the object, and a white thick board held on a stand, as the screen.
Student C used a well illuminated laboratory window grill as the object and a white paper sheet held on a stand as the screen.
Student D used a well illuminated distant tree as the object and a white thick board held on a stand, as the screen.
Arrange these techniques in order of decreasing accuracy in measurement.

B,D,C,A

D,B,C,A

D,C,A,B

B,C,A,D

Question 10 of 20

11. A magnifying glass is a

Both convex and concave

Concave lens

Diverging lens

Convex Lens

Question 11 of 20

12. Is the optical centre always at the centre of lens?

Never

Only if both the curved surfaces are asymmetrical

Only if both the curved surfaces are symmetrical

Yes

Question 12 of 20

13. Where should an object be placed in front of a convex lens to get a real image of the size of the object?

At infinity

At twice the focal length

Between the optical centre of the lens and its principal focus.

At the principal focus of the lens

Question 13 of 20

14. The maximum image distance in case of a concave lens of focal length ‘f’ is :

Question 14 of 20

15. The image formed by a convex lens is virtual when

Object is at focus

Object lie between F and O

Object is at infinity

Object lie between 2F and F

Question 15 of 20

16. Drop of water behaves likes a

Diverging lens

Concave lens

Convex lens

Both convex and concave

Question 16 of 20

17. A lens which forms a virtual and enlarged image is

Convex lens

Concave lens

Diverging lens

Both convex and concave

Question 17 of 20

18. To determine the focal length of convex lens by obtaining a sharp image of a distant object we generally follow the following steps which are not in proper sequence.

(a) Hold the lens between the object and the screen

(b) Measure the distance between the lens and the screen

(c) Select a well lit distant object

(d) Adjust the position of the lens to form a sharp image

The correct sequence will be:

c, a, d, b

c, d, b, a

a, c, d, b

c, d, a, b

Question 18 of 20

19. The image formed by a convex lens is observed to be virtual, erect and larger than the object. Then the position of the object should be

beyond the centre of curvature

at the centre of curvature

between the focus and the centre of curvature

between the pole and focus

Question 19 of 20

20. The lens which is used to correct myopia (shortsightedness) is

Both convex and concave

Concave lens

Converging lens

Convex Lens

Question 20 of 20