Read the following passage carefully:

Attempt the following questions based on the passage:

When the diode is forward biased, it is found that beyond forward voltage $\mathrm{V} = {\mathrm{V}}_{\mathrm{k}}$ , called knee voltage, the conductivity is very high. At this value of battery biasing for p-n junction, the potential barrier is overcome and the current increases rapidly with increase in forward voltage. When the diode is reverse biased, the reverse bias voltage produces a very small current about a few microamperes which almost remains constant with bias. This small current is reverse saturation current.

Attempt the following questions based on the passage:

The V-I characteristic of a diode is shown in the figure. The ratio of forward to reverse bias resistance is