The junction diode in the following circuit requires a minimum current of `1 mA` to be above the knee point `(0.7 V)` of its `I-V` characterstic curve. The voltage across the diode is independent of current above the knee point. If `V_(B)=5 V`, then the maximum value of `R` so that the voltage is above the knee point, will be

Options

A. `4.3 k Omega`
B. `860 k Omega`
C. `4.3` Omega`
D. `860 Omega`

Answer

A

Explanation

`i=(5-0.7)/(R)`
`impliesR=(4.3)/(1xx10^(-3))=4.3kOmega`