CameraIcon

SearchIcon

MyQuestionIcon

55

You visited us 55 times! Enjoying our articles? Unlock Full Access!

Optical Fiber

If two struct...

Question

If two structures of same cross-sectional area, but different numerical apertures NA $_{1}$ and $N A_{2} (N A_{2} < N A_{1})$ are joined longitudinally, the numerical aperture of the combined structure is

A

\frac{N A_{1} N A_{2}}{N A_{1} + N_{2}}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

B

N A_{1} + N A_{2}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

C

N A_{1}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

D

N A_{2}

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

Open in App

Solution

The correct option is D $N A_{2}$
$N A_{2} < N A_{1}$
$\Rightarrow i_{m 2} < i_{m 1}$
If the combination is placed in any order, Total internal Reflection if satisfied for lower $i_{m}$ , it can be satisfied for any lower angles as well.
$∴$ $N A_{2}$ will be the numerical aperture of the combined structure.

Suggest Corrections

thumbs-up

0

Similar questions

Q. If two structure of same cross-sectional area, but different numerical apertures

N A_{1}

N A_{2} (N A_{2} < N A_{1})

are joined longitudinally, the numerical aperture of the combined structure is

Q. Light guidance in an optical fibre can be understood by considering a structure comprising of thin solid glass cylinder of refractive index

n_{1}

surrounded by a medium of lower refractive index

n_{2}

.
The light guidance in the structure takes place due to successive total internal reflections at the interface of the media

n_{1}

n_{2}

as shown in the figure. All rays with the angle of incidence

i

less than a particular value

i_{m}

are confined in the medium of refractive index

n_{1}

. The numerical aperture (NA) of the structure is defined as

sin i_{m}

.

If two structures of same cross-sectional area, but different numerical apertures NA

_{1}

N A_{2} (N A_{2} < N A_{1})

are joined longitudinally, the numerical aperture of the combined structure is

Q. Light guidance in an optical fibre can be understood by considering a structure comprising of thin solid glass cylinder of refractive index

n_{1}

surrounded by a medium of lower refractive index

n_{2}

.
The light guidance in the structure takes place due to successive total internal reflections at the interface of the media

n_{1}

n_{2}

as shown in the figure. All rays with the angle of incidence

i

less than a particular value

i_{m}

are confined in the medium of refractive index

n_{1}

. The numerical aperture (NA) of the structure is defined as

sin i_{m}

.

If two structures of same cross-sectional area, but different numerical apertures NA

_{1}

N A_{2} (N A_{2} < N A_{1})

are joined longitudinally, the numerical aperture of the combined structure is

a_{1}, a_{2}, a_{3}, . . ., a_{n}

are in A.P. with

s_{n}

as the sum of first 'n' terms

(S_{0} = 0), t h e n \sum_{k = 0}^{n}^{n} C_{k} S_{k}

Q. What will be the limit of resolution of a microscope if its numerical aperture is 0.12 and the wavelength of the light used is 6000

A^{0}

(numerical aperture =

μ sin 0

View More

Join BYJU'S Learning Program

similar_icon

Related Videos

lock

TIR Applications

PHYSICS

Watch in App

explore_more_icon

Explore more

Standard XII Physics

Join BYJU'S Learning Program

CrossIcon