Question

does the focal length is same for all mediums in the mirror​

Answer 1

no,

focal length is dependent on refractive index

so when medium of mirror changed

the focal length also changes even though thickness and aperture remains the same

Answer 2

hey mate!!
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→ No, focal length is not same in all mediums.It changes according to medium.

depends upon refractive index of medium

→ It is inversely proportional to refractive iindex of medium.

→Higher the refractive index lower will be focal length.

hope it helps!!

#Jaihind