A `PN` junction diode when forward biased has a drop of `0.5 V` which is assumed to be independent of current. The current in excess of `10 mA` through the diode produces large joule heating which damages the diode. If we diode, the resistor used in series with the diode so that the maximum current does not exceed `5 mA` is.
.

Options

A. `2 xx 10^(2) Omega`
B. `2 xx 10^(5) Omega`
C. `2 xx 10^(3) Omega`
D. `2 xx 10^(4) Omega`

Answer

A

Explanation

`R=(E-V_(b))/(i) =(1.5 -0.5)/(5 xx 10^(-3)) =(1)/(5 xx 10^(-3))`
`=0.2' 10^(3) = 2' 10^(2) W`.