IIT JEE , AIEEE Forum - Physics , General - units and dimensions do we have to learn these??i will surely rate u.

sinjan.j

in the beginning of the chapter i see a heading called " What is physics??" and "scopes and excitement".

Do i have to go through these??

please tell fast!!!!

rakesh61

No sinjan not at all

just go through the law of homogentity

Methods to write dimensional formula

Dimesion formula of some topic like boltzman costant etc they may be given in form of table

How to write dimension formula of a derived unit in term of other derived init

eg pressaure in form of force and (volume or area)

Hope u are clear refer syllabus

Bye

priyesh

no it is not at all neccessary

there are some basic dimensions like L,M,T, etc.....

& some conversions like 1nm = 10^-9m

1 angstrom = 10^-10 m

1 picometer = 10^-12m

etc...etc...

these are basically smaller units of a unit

if u know these it's enough there is no need in learning all the derived units & dimensions just learn the basic units & u can easily derive the rest units

using the basic ones

gomurali

Sinjan, i suggest u to read this atleast for information sake. u r studying physics. So i feel that u should know the importance of physics, though it is not necessary for exam sake.

kamalasai

just go through
but there is no need of remembering...........
the important thing to remember in Units and Dimensions is

Physical Quantity , expression , Dimensional Formula & Units

Application of Dimensional Analysis

a)Conversion of one system of units into another

b)To check the correctness of an equation

c)To derive the relationship between different physical quantity

Principal of Homogeneity of Dimension

hope these are useful for entrance exams...............

asmit

I think Kamalasai and my other friends have answered everything satisfactorily.I would just add that for entrance exams you don't need those topics you mentioned.Besides,there are certain units you will be unfamiliar with which you will learn later.Be careful in that regard.I believe Kamalasai has given the perfect answer to your query.The dimensional analysis part comes with experience.You may find it meaningless initially but as you keep solving more problems of individual chapters,you will automatically feel the need to check the dimensional correctness of an equation.

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