Ray Optics (NEET (National Eligibility cum Medical Entrance Test) Physics): Questions 38 - 41 of 105

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Question number: 38

» Ray Optics » Lens Maker's Formula and Lens Formula

MCQ▾

Question

A convex lens of focal length 10.0 cm is placed in contact with a convex lens of 15.0 cm focal length. What is the focal length of the combination?

Choices

Choice (4) Response

a.

4 cm

b.

12 cm

c.

8 cm

d.

6 cm

Question number: 39

» Ray Optics » Lens Maker's Formula and Lens Formula

Assertion-Reason▾

Assertion (Ꭺ)

The focal length of lens changes when red light is replaced by blue light.

Reason (Ꭱ)

The focal length of lens does not depend on color of light used.

Choices

Choice (4) Response

a.

Ꭺ is false but Ꭱ is true

b.

Both Ꭺ and Ꭱ are false

c.

Both Ꭺ and Ꭱ are true and Ꭱ is the correct explanation of Ꭺ

d.

Ꭺ is true but Ꭱ is false

Question number: 40

» Ray Optics » Deviation and Dispersion of Light by a Prism

Assertion-Reason▾

Assertion (Ꭺ)

Dispersion of light occurs because velocity of light in a material depends upon its color.

Reason (Ꭱ)

The dispersive power depends only upon the material of the prism, not upon the refracting angle of the prism.

Choices

Choice (4) Response

a.

Both Ꭺ and Ꭱ are true and Ꭱ is the correct explanation of Ꭺ

b.

Both Ꭺ and Ꭱ are true but Ꭱ is NOT the correct explanation of Ꭺ

c.

Ꭺ is false but Ꭱ is true

d.

Both Ꭺ and Ꭱ are false

Question number: 41

» Ray Optics » Reflection and Refraction of Light » Smooth Surface

MCQ▾

Question

In an experiment to determine the focal length (f) of a concave mirror by the u - v method, a student places the object pin A on the principal axis at a distance x from the pole P. The student looks at the pin and its inverted image from a distance keeping his/her eye in line with PA. When the student shifts his/her eye towards left, the image appears to the right of the object pin. Then,

Choices

Choice (4) Response

a.

x < f

b.

x = 2 f

c.

f < x < 2f

d.

x > If

f Page
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