Question

The reading of the ammeter for a silicon diode in the given circuit is:

• A. $11·5mA$
• B. $13·5mA$
• C. $0$
• D. $15mA$

Answer 1

The correct option is A

$11·5mA$

Step 1: Given the data & figure

$Voltage\left(V\right)=3V$

$Resistance\left(R\right)=200\Omega$

Step 2: Formula used

The current can be computed using the following formula:

$I=\frac{V}{R}$, where $I=$current, $V=$voltage, and $R=$resistance

Step 3: Compute the current

From the figure, it is clear that the diode is in forward bias.

And we are aware that silicon has a potential barrier of $0·7V$. This means that a voltage of at least $0·7V$ must be provided in order to operate a silicon diode. Therefore, The current in the circuit is,

$\begin{array}{rcl}I& =& \frac{V-∆V}{R}\\ & =& \frac{3-0·7}{200}\\ & =& \frac{2·3}{200}\\ & =& 11·5mA\end{array}$

Thus, the reading of the ammeter is $11·5mA$.

Hence, option A is the correct answer.