CBSE Class 10 Science 2019 · Paper 31/3/1 · Question 26(b)

Light - Reflection and Refraction 2 marks Easy

A student has to trace the path of a ray of light passing through a rectangular glass slab for four different values of angle of incidence.

(a)Write two important precautions for this experiment.
(b)List two conclusions the student will draw based on his experiment.

Answer

Fix the pins vertically and keep $i$ between $3 0^{\circ}$ and $6 0^{\circ}$ ; the emergent ray is parallel to the incident ray but shifted sideways.

(a) Any two: (1) The pins should be fixed vertically, in a straight line and at least

3

cm apart, and their feet should be lined up while fixing

P_{3}

and

P_{4}

. (2) The angle of incidence should be between

3 0^{\circ}

and

6 0^{\circ}

. (3) The glass slab must not be moved during the experiment; it should always stay within the outline drawn round it. (b) Any two: (1) The emergent ray is parallel to the incident ray: the angle of emergence equals the angle of incidence,

∠ e = ∠ i

. (2) The emergent ray is shifted sideways from the line of the incident ray (lateral displacement). (3) The ray bends towards the normal on entering the glass slab (

∠ r < ∠ i

) and away from the normal on leaving it.

🔒 Step-by-step solution

CBSE Class 10 Science 2019 · Paper 31/3/1 · Question 26(b)

Answer

From the board papers

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