Lenses & Lens Maker's Formula — NEET Physics practice

Question 1

A wire mesh of very small squares is viewed at 8 cm through a converging lens of focal length 10 cm held close to the eye. The magnification produced is:

Accepted Answer

5

Answer

8

Answer

10

Answer

20

Question 2

A 5 cm needle placed 45 cm from a lens forms an image on a screen 90 cm on the other side. What is the size of the image, and the focal length of the lens?

Accepted Answer

−10 cm, 30 cm

Answer

10 cm, 30 cm

Answer

100 cm, 10 cm

Answer

1 m, 100 cm

Question 3

Read Statement A and Statement B carefully and choose the correct option. Statement A: When an object is placed at the centre of curvature of a concave lens, its image is formed at the centre of curvature on the other side. Statement B: A concave lens always forms a virtual and erect image (of a real object).

Accepted Answer

Statement A is false, but Statement B is true.

Answer

Both Statement A and Statement B are true.

Answer

Statement A is true, but Statement B is false.

Answer

Both Statement A and Statement B are false.

Question 4

Read the Assertion and Reason carefully and choose the correct option. Assertion: When light passes through a thin lens, it refracts twice — once at each surface. Reason: A thin lens is a piece of transparent material bounded by two spherical surfaces (or one spherical and one plane).

Accepted Answer

Both Assertion and Reason are true, and Reason is the correct explanation of Assertion.

Answer

Both Assertion and Reason are true, but Reason is NOT the correct explanation of Assertion.

Answer

Assertion is true, but Reason is false.

Answer

Assertion is false, but Reason is true.

Question 5

Read the Assertion and Reason carefully and choose the correct option. Assertion: The lens maker's formula relates the focal length of a lens to the radii of curvature of its two surfaces and its refractive index. Reason: The lens maker's formula is derived by applying the refraction formula at each spherical surface and adding the two equations.

Accepted Answer

Both Assertion and Reason are true, and Reason is the correct explanation of Assertion.

Answer

Both Assertion and Reason are true, but Reason is NOT the correct explanation of Assertion.

Answer

Assertion is true, but Reason is false.

Answer

Assertion is false, but Reason is true.

Question 6

Read Statement A and Statement B carefully and choose the correct option. Statement A: A convex lens forms a real image when the object is placed beyond its focal length. Statement B: The image formed by a convex lens is always inverted when it is real.

Accepted Answer

Both Statement A and Statement B are true.

Answer

Statement A is true, but Statement B is false.

Answer

Statement A is false, but Statement B is true.

Answer

Both Statement A and Statement B are false.

Question 7

Match the quantities in refraction at spherical surfaces (Column I) with their sign conventions or meanings (Column II). Column I: Object distance (u); Image distance (v); Radius of curvature (R); Lens power (P) Column II: Reciprocal of focal length (1/f); Positive when the centre of curvature is on the side opposite to the incoming light; Positive when the image is formed on the side opposite to the incoming light; Negative when the object is on the same side as the incoming light

Accepted Answer

A→S, B→R, C→Q, D→P

Answer

A→R, B→S, C→P, D→Q

Answer

A→R, B→S, C→Q, D→P

Answer

A→Q, B→P, C→S, D→R

Question 8

Match the lens and refraction formulas (Column I) with their equations or meanings (Column II). Column I: Refraction at a spherical surface; Thin lens formula; Lens maker's formula; Refractive indices (n₁, n₂) Column II: 1/v − 1/u = 1/f; n₂/v − n₁/u = (n₂ − n₁)/R; Indicate the speed of light in different media; 1/f = (n₂₁ − 1)(1/R₁ − 1/R₂)

Accepted Answer

A→Q, B→P, C→S, D→R

Answer

A→S, B→P, C→R, D→Q

Answer

A→R, B→S, C→P, D→Q

Answer

A→Q, B→R, C→S, D→P

Question 9

Match the concepts (Column I) with their descriptions (Column II). Column I: Refraction by lenses; Image formed by a concave lens; Total internal reflection; Refractive index Column II: Occurs when light goes from denser to rarer medium and the angle of incidence exceeds the critical angle; Ratio of the speed of light in vacuum to that in the medium; Follows the lens maker's formula; Virtual, erect and diminished

Accepted Answer

A→R, B→S, C→P, D→Q

Answer

A→R, B→S, C→Q, D→P

Answer

A→P, B→R, C→S, D→Q

Answer

A→S, B→P, C→Q, D→R

Lenses & Lens Maker's Formula: NEET practice questions

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Refraction & Total Internal Reflection

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