The output (Y) of logic circuit given below is 0 only when :

The angular momentum of an electron in a hydrogen atom is proportional to : (Where $$\mathrm{r}$$ is the radius of orbit of electron)

The vehicles carrying inflammable fluids usually have metallic chains touching the ground:

A galvanometer of resistance $$100 \Omega$$ when connected in series with $$400 \Omega$$ measures a voltage of upto $$10 \mathrm{~V}$$. The value of resistance required to convert the galvanometer into ammeter to read upto $$10 \mathrm{~A}$$ is $$x \times 10^{-2} \Omega$$. The value of $$x$$ is :