Numerical aperture of an optical fiber is a measure of

light gathering power of the fiber

attenuation of light signals in the fiber

difference between the refractive indices of core and the cladding

A ray of laser of a wavelength 630 nm is incident at an angle of 30 ° at the diamond-air interface. It is going from diamond to air. The refractive index of diamond is 2 . 42 and that of air is 1 . Choose the correct option.

Angle of refraction is 24 . 41 ° .

Angle of refraction is 53 . 4 ° .

E M B I B E

Physics Crash Course NDA & NA EE>Chapter 21 - Ray Optics>Exercise 1>Q 10

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IMPORTANT

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Focal length, radius of curvature and power of a plane mirror respectively are

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Important Questions on Ray Optics

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IMPORTANT

Physics Crash Course NDA & NA EE>Chapter 21 - Ray Optics>Exercise 1>Q 11

A mirror is placed at an angled of $30 °$ with respect to $y -$ axis (see figure). A light ray travelling in the negative $y -$ direction strikes the mirror. The direction of the reflected ray is given by the vector

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IMPORTANT

Physics Crash Course NDA & NA EE>Chapter 21 - Ray Optics>Exercise 1>Q 12

A concave mirror of focal length

15 cm

, forms an image having twice the linear dimensions of the object. The position of the object, when the image is virtual, will be

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IMPORTANT

Physics Crash Course NDA & NA EE>Chapter 21 - Ray Optics>Exercise 1>Q 13

A convex mirror has a focal length

f .

A real object is placed at a distance

f

in front of it from the pole, then it produces an image at-

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Physics Crash Course NDA & NA EE>Chapter 21 - Ray Optics>Exercise 1>Q 14

If a concave mirror of focal length

10 cm

is immersed in water, its focal length will

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IMPORTANT

Physics Crash Course NDA & NA EE>Chapter 21 - Ray Optics>Exercise 1>Q 15

In a motor car, spherical mirrors are utilised at two different places,
(i) the head light and
(ii) rear view mirror. What type of mirrors are used?

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IMPORTANT

Physics Crash Course NDA & NA EE>Chapter 21 - Ray Optics>Exercise 1>Q 16

A short linear object $O$ is placed on the principal axis of convex mirror of focal length $f$ as shown in the figure. The ratio of transverse magnification to longitudinal magnification is :

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