13
MCQ (Multiple Correct Answer)
In the depletion region of a diode
A
there are no mobile charges
B
equal number of holes and elections exist, making the region neutral
C
recombination of holes and electrons has taken place
D
immobile charged ions exist
14
MCQ (Multiple Correct Answer)
What happens during regulation action of a Zener diode?
A
The current and voltage across the Zener remains fixed
B
The current through the series Resistance $\left(R_s\right)$ changes
C
The Zener resistance is constant
D
The resistance offered by the Zener changes
15
MCQ (Multiple Correct Answer)
To reduce the ripples in rectifier circuit with capacitor filter
A
$R_L$ should be increased
B
input frequency should be decreased
C
input frequency should be increased
D
capacitors with high capacitance should be used
16
MCQ (Multiple Correct Answer)
The breakdown in a reverse biased $p-n$ junction is more likely to occur due to
A
large velocity of the minority charge carriers if the doping concentration is small
B
large velocity of the minority charge carriers if the doping concentration is large
C
strong electric field in a depletion region if the doping concentration is small
D
strong electric field in the depletion region if the doping concentration is large
17
Subjective
Why are elemental dopants for Silicon or Germanium usually chosen from group XIII or group XV?
Explanation
The size of the dopant atom should be such that their presence in the pure semiconductor does not distort the semiconductor but easily contribute the charge carriers on forming covalent bonds with Si or Ge atoms, which are provided by group XIII or group XV elements.