# Which of the following statement is incorrect ?

(a)An ideal diode is an open switch

(b)Diode acts as a rectifyer

(c)a diode does not obey ohm's law

(d)When p and of diode is connected to negative terminal it behaves like an insulator

An ideal diode does not behave like an open switch , it behaves like a one way conductor, and does not obey ohm's law.
Hence c is the correct answer.