Question

(a)

(b)

1. Name the type of a diode whose characteristics are shown in figure (A) and figure (B).
2. What does the point P in figure (A) represent?
3. What does the points P and Q in figure (B) represent?

Answer 1

1. Figure (a) represents the characteristics of the Zener diode and curve (b) is of the solar cell.
2. In figure (a), point P represents Zener breakdown voltage.
3. 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.