Advertisements
Advertisements
Question
 (a) |
 (b) |
- Name the type of a diode whose characteristics are shown in figure (A) and figure (B).
- What does the point P in figure (A) represent?
- What does the points P and Q in figure (B) represent?
Advertisements
Solution
- Figure (a) represents the characteristics of the Zener diode and curve (b) is of the solar cell.
- In figure (a), point P represents Zener breakdown voltage.
- In figure (b), point Q represents zero voltage and negative current. This means the light falling on the solar cell with at least a minimum threshold frequency gives the current in opposite direction to that due to a battery connected to solar cell. But for point Q the battery is short-circuited. Hence it represents the short circuit current. And the point Pin fig. (b) represents some open circuit, the voltage on solar cell with zero current through solar cell.
It means, there is a battery connected to a solar cell which gives rise to the equal and opposite current to that in a solar cell by virtue of light falling on it.
APPEARS IN
RELATED QUESTIONS
(i) Explain with the help of a diagram the formation of depletion region and barrier potential in a pn junction.
Explain the working of P-N junction diode in forward and reverse biased mode.
When a forward bias is applied to a p-n junction, it ______.
Draw a labelled diagram of a full wave rectifier. Show how output voltage varies with time if the input voltage is a sinusoidal voltage.
Show on a graph, the variation of resistivity with temperature for a typical semiconductor.
In a photo diode, the conductive increases when the material is exposed to light. It is found that the conductivity changes only if the wavelength is less than 620 nm. What is the band gap?
(Use Planck constant h = 4.14 × 10-15 eV-s, Boltzmann constant k = 8·62 × 10-5 eV/K.)
Answer the following question.
Why photodiodes are required to operate in reverse bias? Explain.
The current through an ideal PN-junction shown in the following circuit diagram will be:
In a semiconductor diode, the barrier potential offers opposition to only
Avalanche breakdown is due to ______.
In the depletion region of a diode ______.
- there are no mobile charges.
- equal number of holes and electrons exist, making the region neutral.
- recombination of holes and electrons has taken place.
- immobile charged ions exist.
If each diode in figure has a forward bias resistance of 25 Ω and infinite resistance in reverse bias, what will be the values of the current I1, I2, I3 and I4?
Differentiate between the threshold voltage and the breakdown voltage for a diode.
Write the property of a junction diode which makes it suitable for rectification of ac voltages.
Explain the formation of the barrier potential in a p-n junction.
A semiconductor device is connected in series with a battery, an ammeter and a resistor. A current flows in the circuit. If. the polarity of the battery is reversed, the current in the circuit almost becomes zero. The device is a/an ______.
Describe the following term briefly:
minority carrier injection in forward biasing.
Describe the following term briefly:
breakdown voltage in reverse biasing
What is meant by forward biasing of a semiconductor diode?
Choose the correct circuit which can achieve the bridge balance.
