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Sound wave needs medium to travel
as energy which travels in this wave is because of transfer from one particle to another particle
If there is no medium then energy can not be transferred and sound wave will not travel
so in vacuum we can not listen sound
similarly here air is removed it means there is no medium inside the jar to travel the sound and hence we can not hear it
Option B is correct
Without air, the sound waves cannot travel to the ear.
Answer:
Explanation:
λ = wave length = 632 x 10⁻⁹
slit width a = 2 x 10⁻³ m
angular separation of central maxima
= 2 x λ /a
= 2 x 632 x 10⁻⁹ / 2 x 10⁻³
= 632 x 10⁻⁶ rad
width in m of light spot.
= 632 x 10⁻⁶ x 376000 km
= 237.632 km
Divide CFU of Dilution. Divide the CFU of the dilution (the number of colonies you counted) by the result from step 4. For this example, you work out 46 ÷ 1/1000, which is the same as 46 x 1,000. The result is 46,000 CFU in the original sample.
