The cut-off wavelength (in µm) of light that can be used for intrinsic excitation of a semiconductor material of bandgap E_g= 1.1 eV is ________.

Consider a silicon sample doped with N_D = 1×10¹⁵/cm³ donor atoms. Assume that the intrinsic carrier concentration n_i = 1.5×10¹⁰/cm³. If the sample is additionally doped with N_A = 1×10¹⁸/cm³ acceptor atoms, the approximate number of electrons/cm³ in the sample, at T=300 K, will be _________________.

An N-type semiconductor having uniform doping is biased as shown in the figure.

If E_C is the lowest energy level of the conduction band, E_V is the highest energy level of the valance band and E_F is the Fermi level, which one of the following represents the energy band diagram for the biased N-type semiconductor?

For a right angled triangle, if the sum of the lengths of the hypotenuse and a side is kept constant, in order to have maximum area of the triangle, the angle between the hypotenuse and the side is