Chapter 29, Problem 25P

To determine

The amount of current flows in the circuit.

Answer to Problem 25P

  $13mA$ .

Explanation of Solution

Given:

Resistor, $R=0.100k\Omega$

Voltage of battery, $V_{battery}=2V$

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 ${\text{V}}_{\text{battery}}={\text{V}}_{\text{diode}}+{\text{V}}_{\text{R}}$

  $\therefore 2.0\text{V}=\text{V}\left(\text{I}\right)+\text{I}\left(0.100\text{k}\Omega \right)$

  $\therefore \text{V}\left(\text{I}\right)=2.0\text{V}-\text{I}\left(0.100\text{k}\Omega \right)$

This straight line passes through $\left(20mA,0V\right)\&\left(12mA,0.8V\right)$ , as drawn in figure.

  

As $V\left(I\right)$ is denoted by both curves, the intersection point will give the current.

Hence, the current is $13mA$ .

Conclusion: The required current is $13mA$ .