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

Options

A. `4.3kOmega`
B. `5.5kOmega`
C. `4.8kOmega`
D. `8.6kOmega`

Answer

A

Explanation

At knee point voltage across the diode is 0.7 V
Hence voltage across resistance R is 5 - 0.7
`=4.3V`
usig `V = iR implies 4.3 = 1xx10^(-3)xxR implies R = 4.3kOmega`