Question

when Dal is cooked in pressure cooker the pressure cooker inner surface become black why

Answer 1

because the Dalprobably gets burnt

Answer 2

Hello dear your answer is in down

when is cooked in a pressure cooker the inner surface of pressure cooker becomes black due to incomplete combustion reaction of of fuel which results in soot.

Next reason
When dal is cooked in pressure cooker pressure cooker inner surface becomes black because may be the dal has been cooked for two times or may be water has been used to cook dal

But in case 1 reason may be your answer