Three photodiodes $$D_1, D_2$$ and $$D_3$$ are made of semiconductors having band gaps of $$2.5 \mathrm{~eV}, 2 \mathrm{~eV}$$ and $$3 \mathrm{~eV}$$, respectively. Which one will be able to detect light of wavelength $$600 \mathrm{~nm}$$ ?

In the following circuit what are P and Q

A positive hole in a semiconductor is

The conductivity of semiconductor increases with increase in temperature because