What is the dc component of the output voltage if a sinusoidal signal of 33 V peak voltage is the input of a half wave diode rectifier circuit?

An intrinsic semiconductor has equal concentrations of hole and electron which is equal to $4 \times 10^8 \mathrm{~m}^{-3}$. During its conversion to extrinsic semiconductor, concentration of hole increases to $8 \times 10^{10} \mathrm{~m}^{-3}$. The new electron concentration is:

Three ideal diodes and resistors connected to the cell of negligible internal resistance is as shown. Find the current passing through the $10 \Omega$ resistor.

Diamond is considered as an insulator because