If a wave is going from one medium to another, then

An electomagnetic wave is entering from one medium to another. Then the property which remains unaltered is

When a wave goes from one medium to another , there is a change in ………. .

When a sound wave goes from one medium to another, the quantity that remains unchanged is :

When a sound wave goes from one medium to another, the quantity X remains unchanged. X is

When a wave travels from one medium to another, the quality which will not change is its