A lens immersed in a transparent liquid becomes invisible. Under what condition does it happen ?

A lens immersed in a transparent liquid becomes invisible. Under what condtion does it happen ?

A glass lens of refractive index 1.45 when immersed in a transparent liquid becomes invisible. Under what condition does it happen ?

A glass lens of refractive index 1.45 when immersed in a transparent liquid becomes invisible. Under what condition does it happen ?

A lens when immersed in a transparent liquid becomes invisible. Under what condition does it happen?

Sometimes the balance point in the potentiometer may not be obtained on the wire of the potentiometer . Under what condition does it happen ?

Under what conditions does aluminium reacts with water?

When unpolarized ligth passes from air to a transparent mediu,under what condition does the refleced ligth get polarize?