A vernier callipers has 20 divisions on the vernier scale, which coincides with $$19^{\text {th }}$$ division on the main scale. The least count of the instrument is $$0.1 \mathrm{~mm}$$. One main scale division is equal to ________ mm.

The ratio of heat dissipated per second through the resistance $$5 \Omega$$ and $$10 \Omega$$ in the circuit given below is:

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)