If a mirror reverses right and left, why doesn't it reverse up and down?

Why is photodiode used in reverse bias ?

A single pole doesn't exist . Why ?

why are reversible process non-static ?

Assertion (A): During reverse, biasing a diode doesn't conduct current. Reason (R) : It narrows the depletion layer.

Assertion (A): During reverse, biasing a diode doesn't conduct current. Reason (R) : It narrows the depletion layer.

Why does a photo-diode function in reverse bias?

Answer the following : At the sea level the atmospheric pressure 101 x 10^3 Pa is acting on a table top of size 1 m^2 . Under such a heavy pressure , why doesn't the table top crumble down ?