Chapter 29, Problem 24P

To determine

The voltage needed to produce a given current.

Answer to Problem 24P

  $12.2V$ .

Explanation of Solution

Given:

Resistor, $R=960\Omega$

Current, $I=12\times {10}^{-3}A$

Formula used:

It is known that: ${\text{V}}_{\text{battery}}={\text{V}}_{\text{diode}}+{\text{V}}_{\text{R}}$

Where,

  ${\text{V}}_{\text{diode}}$ is the voltage of diode.

  ${\text{V}}_{\text{R}}$ is the voltage at resistor.

  ${\text{V}}_{\text{battery}}$ is the voltage of battery.

Calculation:

The voltage of battery is ${\text{V}}_{\text{battery}}={\text{V}}_{\text{diode}}+{\text{V}}_{\text{R}}$

  $\therefore {\text{V}}_{\text{battery}}=0.68\text{}\text{V}+\left(12\times {10}^{-3}\text{A}\right)\left(960\Omega \right)=12.2\text{V}$

Conclusion: The required voltage is $12.2\text{V}$ .