IIT JEE , AIEEE Forum - Physics , Optics - important difference between sound and light waves explain this!!!

eistien

hey everybody!

its given in arihant

its given that for light waves water is a denser medium with respect to air

but for sound waves water is rarer medium with respect to air what makes that difference !!! please explain !!!! rates assured!!!!

newarnav

Denser Media means velocity of wave considered is less then the velocity in other medium (rareer medium)

For sound

v =sqr root(B/d) [where B is Bulk Modulas and d is density]

formula tells that V_sound in air is less(many times) than in water hence it(air) is denser wrt water

and

for light

we know it is V_water V_air /

that is ,speed is less in water and hence it is a denser media wrt air

hoorey !! we have done it

kuch samajh mai aaya ?

suresan

Denser and rarer mediums are defined according to the propogation properties. The denser the medium the refractive index will be higher and the velocity lower. For mechanical waves like sound the velocity in a medium is charectarised by the density(M/V) and elastic modulus.But for light waves(E M waves) the propogation properties like speed are charectrised bu permiability and permitivity( Magnetic and Electric properties of the medium).
Then you see that there is no definite relationship between the velocity of sound waves in a medium and the velocity of light waves in that medium

srivathsan.v

Light wave is transverse in nature. The electric and magnetic components are affected with the no. of atoms. Thus, with the increase in density, speed of light waves increase.
In the case of sound waves, speed increases with the increase in the bulkmodulus of elasticity.
I think that it is the reason.

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