Why do we need optical instruments for?

Monjur Alahi

Why do we need optical instruments for?


0 like 0 dislike
2 views
Share with your friends

1 Answers

Salim Ahmed Kawsar

Call

i. Due to the limitation for focusing the eye lens it is not possible to take an object closer than a certain distance. This distance is called least distance of distance vision D. For a normal, unaided human eye D = 25 cm.

ii. If an object is brought closer than this, we cannot see it clearly.

iii. If an object is too small the corresponding visual angle from 25 cm is not enough to see it and if we bring it closer than that, its image on the retina is blurred.

iv. Also, the visual angle made by cosmic objects far away from us such as stars is too small to make out minor details and we cannot bring those closer.

v. In such cases we need optical instruments like microscope and telescopes to observe these things clearly.

0 like 0 dislike
2 views
Talk Doctor Online in Bissoy App
Write the formula for optical purity & enantiomeric excess.

Correct Answer - `%"Optical purity" = ("observed optical rotaion")/("optical rotation of pure enantiomer") xx 100` `%"Enantiomeric excess" = (|d-l|)/(d+l) xx 100 = ("excess of one enantiomer over other")/("entire mixture") xx...

2 Answers 1 views
The highest level need in the need Hierachy of Abraham Maslow :

Correct Answer - c.) Self-actualisation need

2 Answers 1 views
Primarily cells are studied under  A) optical microscope 

A) optical microscope

2 Answers 1 views
The main principle behind working of optical fibres is ………………….. 

A) total internal reflection

2 Answers 1 views
A bunch of optical fibres causes a ……………………..

B) light pipe

2 Answers 1 views
Identify any two charts type and two Instruments required for chart work.

Various Types of Charts.  (a) Navigational Chart.  (b) Ship`s boat charts.  (c) Routing charts.  (d) Magnetic charts.  (e) Ocean sounding charts.  (f) LD charts (lattice Decca).  (g) Astronomical charts and diagrams.  Instruments required for chart work  a) Dividers  b) Compass  c)...

2 Answers 1 views
It is a market for medium and long term instruments having a period of maturity of more than one year is?

(b) Capital market

2 Answers 1 views
What is business finance? Why do businesses need funds? Explain.

Nature of Business Finance:  1. Fixed capital requirements: In order to start a business funds are needed to purchase fixed assets like land and building, plant and machinery. This is called fixed...

2 Answers 1 views
Discuss the financial instruments used in international financing.

International Financing:  1. Commercial Banks:  Commercial banks all over the world extend foreign currency loans for business purposes. Standard chartered is a major source of foreign currency loan to the Indian industry. 2....

2 Answers 1 views
Why do we need to manage our resources carefully?

Our natural resources are limited. With the rapid increase in human population, due to improvement in health care the demand for all resources is increasing.

2 Answers 1 views