Question

Assertion : A total reflecting prism is used to erect the inverted image without deviation.

Reason: Rays of light incident parallel to base of prism emerge out as parallel rays.

(a) Both A and R are true and R is the correct explanation of A

(b) Both A and R are true but R is not correct explanation of A

(c) A is true but R is false

(d) A and R are false

Answer 1

Correct option (a) Both A and R are true and R is the correct explanation of A

Explanation:

Beam of light incident of face AB, suffers refraction from air to glass and strikes the face AC suffering total internal reflection. The beam now strikes the face BC of the prism at an angle of incidence less than the critical angle hence it suffers refraction from glass to air and bends away from the normal. The beam  emerges out parallel to the base. As a result of refraction, on emergence the rays are inverted.