Carbon, Silicon, and Germanium atoms have four valence electrons each. Their valence and conduction bands are separated by energy band gaps represented by ${\left({\mathrm{E}}_{\mathrm{g}}\right)}_{\mathrm{C}},{}_{}$ ${\left({\mathrm{E}}_{\mathrm{g}}\right)}_{\mathrm{Si}}$, and ${\left({\mathrm{E}}_{\mathrm{g}}\right)}_{\mathrm{Ge}}$ respectively. Which one of the following relationships is true in their case?

1. ${\left({\mathrm{E}}_{\mathrm{g}}\right)}_{\mathrm{C}}<{\left({\mathrm{E}}_{\mathrm{g}}\right)}_{\mathrm{Ge}}$

2. ${\left({\mathrm{E}}_{\mathrm{g}}\right)}_{\mathrm{C}}>{\left({\mathrm{E}}_{\mathrm{g}}\right)}_{\mathrm{Si}}$

3. ${\left({\mathrm{E}}_{\mathrm{g}}\right)}_{\mathrm{C}}={\left({\mathrm{E}}_{\mathrm{g}}\right)}_{\mathrm{Si}}$

4. ${\left({\mathrm{E}}_{\mathrm{g}}\right)}_{\mathrm{C}}<{\left({\mathrm{E}}_{\mathrm{g}}\right)}_{\mathrm{Si}}$

Of the diodes shown in the following diagrams, which one of the diodes is reverse biased?
 

1.		2.
3.		4.

The truth table for the following network is:

Zener diode is used as:
1. Half-wave rectifier
2. Full-wave rectifier
3. AC voltage stabilizer
4. DC voltage stabilizer

The depletion layer has (for an unbiased \(\mathrm{p\text-n}\) junction):
1. electrons
2. holes
3. static ions
4. neutral atoms

In semiconductors at room temperature:

The peak voltage in the output of a half-wave diode rectifier fed with a sinusoidal signal without a filter is \(10~\text V.\) The DC component of the output voltage is:
1. \(\dfrac{10}{\pi }~\text V\) 

2. \(10~\text V\) 

3. \(\dfrac{20}{\pi }~\text V\) 

4. \(\dfrac{10}{\sqrt{2}}~\text V\) 

In a p–n junction photocell, the value of the photo electromotive force produced by monochromatic light is proportional to: