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
What happens when a forward bias is applied to a p-n junction?
What causes the setting up of high electric field even for small reverse bias voltage across the diode?
When a forward bias is applied to a p-n junction, it ______.
With reference to semiconductor devices, define a p-type semiconductor and a Zener diode.
The dynamic plate resistance of a triode value is 10 kΩ. Find the change in the plate current if the plate voltage is changed from 200 V to 220 V.
Of the diodes shown in the following diagrams, which one is reverse biased?
The nature of binding for a crystal with alternate and evenly spaced positive and negatively ions is
In forward bias width of potential barrier in a p + n junction diode
When an electric field is applied across a semiconductor ______.
- electrons move from lower energy level to higher energy level in the conduction band.
- electrons move from higher energy level to lower energy level in the conduction band.
- holes in the valence band move from higher energy level to lower energy level.
- holes in the valence band move from lower energy level to higher energy level.
Consider an npn transistor with its base-emitter junction forward biased and collector base junction reverse biased. Which of the following statements are true?
- Electrons crossover from emitter to collector.
- Holes move from base to collector.
- Electrons move from emitter to base.
- Electrons from emitter move out of base without going to the collector.
The breakdown in a reverse biased p–n junction diode is more likely to occur due to ______.
- large velocity of the minority charge carriers if the doping concentration is small.
- large velocity of the minority charge carriers if the doping concentration is large.
- strong electric field in a depletion region if the doping concentration is small.
- strong electric field in the depletion region if the doping concentration is large.
Can the potential barrier across a p-n junction be measured by simply connecting a voltmeter across the junction?
In the circuit shown in figure, when the input voltage of the base resistance is 10 V, Vbe is zero and Vce is also zero. Find the values of Ib, Ic and β.
Consider a box with three terminals on top of it as shown in figure (a):
 (a) |
Three components namely, two germanium diodes and one resistor are connected across these three terminals in some arrangement. A student performs an experiment in which any two of these three terminals are connected in the circuit shown in figure (b).
 (b) |
The student obtains graphs of current-voltage characteristics for unknown combination of components between the two terminals connected in the circuit. The graphs are
(i) when A is positive and B is negative
 (c) |
(ii) when A is negative and B is positive
 (d) |
(iii) When B is negative and C is positive
|
(e) |
(iv) When B is positive and C is negative
 (f) |
(v) When A is positive and C is negative
 (g) |
(vi) When A is negative and C is positive
 (h) |
From these graphs of current-voltage characteristics shown in figure (c) to (h), determine the arrangement of components between A, B and C.
Differentiate between the threshold voltage and the breakdown voltage for a diode.
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 ______.
What is meant by forward biasing of a semiconductor diode?
An ideal PN junction diode offers ______.
Choose the correct circuit which can achieve the bridge balance.
