Light - Practice Test | ExamPrepSheets

[#321] The focal length of a spherical mirror is . . . . . . . .

(A) double its radius of curvature

(B) three times its radius of curvature

(C) half of its radius of curvature

(D) its radius of curvature

Correct Answer

(C) half of its radius of curvature

[#322] Two glass lenses of same focal length, one being convex and the other concave, are kept in contact, the combination will act as

(A) convergent lens

(B) divergent lens

(C) plane glass sheet

(D) mirror

Correct Answer

(C) plane glass sheet

[#323] Which of the following does not used concave mirror?

(A) search light

(B) solar furnace

(C) rearview mirror

(D) car headlight

Correct Answer

(C) rearview mirror

[#324] The theory belongs behind stars twinkling is that-

(A) The refractive index of the different layers of earth's atmosphere changes continuously, consequently the position of the star's image changes with time

(B) The intensity of light emitted by them changes with time

(C) The light from the star is scattered by the dust particles and air molecules in the earth's atmosphere

(D) The distance of the stars from the earth changes with time

Correct Answer

(A) The refractive index of the different layers of earth's atmosphere changes continuously, consequently the position of the star's image changes with time

[#325] Persons suffering from myopia are advised to use

(A) convex lens

(B) concave lens

(C) plano-convex lens

(D) plano-concave lens

Correct Answer

(B) concave lens

Light - Study Mode

[#321] The focal length of a spherical mirror is . . . . . . . .

Correct Answer

[#322] Two glass lenses of same focal length, one being convex and the other concave, are kept in contact, the combination will act as

Correct Answer

[#323] Which of the following does not used concave mirror?

Correct Answer

[#324] The theory belongs behind stars twinkling is that-

Correct Answer

[#325] Persons suffering from myopia are advised to use

Correct Answer