List of top Science Questions on Light - Reflection and Refraction asked in CBSE Class X, CBSE Compartment X

Identify from the following the ray diagram which shows the correct path of the reflected ray for the ray incident on a concave mirror as shown:

Out of the two media - Medium 1 and Medium 2, in which is the speed of light more?

Name a metal found in the earth's crust:
(i) in free state and
(ii) in the form of its compound.
State where each of these metals are placed in the reactivity series of metals

A student placed a candle flame at different distances from a convex lens and focused its image on a screen. He recorded his observation in tabular form as given below:

Assertion (A): Offsprings produced by asexual reproduction are genetically similar to the parents.
Reason (R): Asexual reproduction involves a single parent.

Assertion (A): The rainbow is a natural spectrum of sunlight in the sky.
Reason (R) : Rainbow is formed in the sky when the sun is overhead and water droplets are also present in air.

Assertion (A): Red light signals are used to stop the vehicles on the road.
Reason (R): Red coloured light is scattered the most so as to be visible from a large distance.

A ray of light is incident on a plane mirror at an angle of incidence of 15°. The deviation in the ray produced by the mirror is:

For an object, a convex mirror always forms an image which is:

At what distance from a convex lens should an object be placed to get an image of the same size as that of the object on a screen ?

The phenomena of light involved in the formation of a rainbow in the sky are

(a) Upper half of a convex lens is covered with a black paper. Draw a ray diagram to show the formation of image of an object placed at a distance of 2F from such a lens. Mention the position and nature of the image formed. State the observable difference in the image obtained if the lens is uncovered. Give reason to justify your answer.
(b) An object is placed at a distance of 30 cm from the optical centre of a concave lens of focal length 15 cm. Use lens formula to determine the distance of the image from the optical centre of the lens.

List four properties of the images formed by a plane mirror.

A 1.5 cm tall candle flame is placed perpendicular to the principal axis of a concave mirror of focal length 12 cm. If the distance of the flame from the pole of the mirror is 18 cm, use the mirror formula to determine the position and size of the image formed.

Draw a ray diagram to show the path of the reflected ray in each of the following cases:
A ray of light incident on a convex mirror
1.parallel to its principal axis,
2. directed towards its principal focus.

A 4 cm tall object is placed perpendicular to the principal axis of a convex lens of focal length 24 cm. The distance of the object from the lens is 16 cm. Find the position and size of the image formed.

Draw a ray diagram to show the path of the refracted ray in each of the following cases:
A ray of light incident on a concave lens
1. parallel to its principal axis,
2. directed towards its principal focus.

Name and explain the phenomenon of light due to which the path of a beam of light becomes visible when it enters a smoke filled room through a small hole. Also state the dependence of colour of the light we receive on the size of the particle of the medium through which the beam of light passes.

“The linear magnification produced by a spherical mirror is +3.”Based on this statement answer the following questions:
(a) What is the type of mirror?
(b) Where is the object located?
(c) List two properties of the image formed (other than the size/magnification).

A highly polished surface such as a mirror reflects most of the light falling on it. In our daily life we use two types of mirrors — plane and spherical. The reflecting surface of a spherical mirrors may be curved inwards or outwards. In concave mirrors, reflection takes place from the inner surface, while in convex mirrors reflection takes place from the outer surface.

(a) State two laws of refraction of light.
(b) Define the term absolute refractive index of a medium. A ray of light enters from vacuum to glass of absolute refractive index 1.5. Find the speed of light in glass. The speed of light in vacuum is \(3 \times 10^8\) m/s.

Study the data given below showing the focal length of three concave mirrors A, B and C and the respective distances of objects placed in front of the mirrors:

Case	Mirror	Focal Length (cm)	Object Distance (cm)
1	A	20	45
2	B	15	30
3	C	30	20

(i) In which one of the above cases the mirror will form a diminished image of the object? Justify your answer.
(ii) List two properties of the image formed in case 2.
(iii) (A) What is the nature and size of the image formed by mirror C? Draw ray diagram to justify your answer.

OR

(iii) (B) An object is placed at a distance of 18 cm from the pole of a concave mirror of focal length 12 cm. Find the position of the image formed in this case.