JEE Main 202528 Jan, Morning shiftPhysicsMediumOptics190× since 2002
A hemispherical vessel is completely filled with a liquid of refractive index . A small coin is kept at the lowest point (O) of the vessel as shown in figure. The minimum value of the refractive index of the liquid so that a person can see the coin from point E (at the level of the vessel) is ______.