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Find the change in diode voltage if the current changes from 0.1 mA to 10 mA.

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User Dimoniy
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2 Answers

7 votes

Final answer:

The question pertains to the change in voltage across a diode as current changes, implying a standard silicon diode maintains approximately 0.7V drop when conducting. Without specific characteristics, the exact voltage change cannot be computed, but it would likely be negligible as the forward voltage drop of a conducting diode does not significantly change across a large range of current levels.

Step-by-step explanation:

The question asks about the change in voltage across a diode when the current through it changes from 0.1 mA to 10 mA. To answer this, we would typically use the diode equation, which is derived from the Shockley ideal diode equation. However, the information given about how the voltage drop across a diode behaves when it conducts suggests we can assume a standard voltage drop across a conducting diode. For silicon diodes, this is typically around 0.7V when the diode is forward-biased and conducting.

Unfortunately, without additional information about the diode's material and characteristics, it is not feasible to calculate the exact change in voltage. Also, the standard voltage drop (approximately 0.7V) will not significantly change over a wide range of current levels, especially for currents higher than the threshold at which the diode begins to conduct well. Therefore, if we assume that we are dealing with a typical silicon diode, the change in voltage would likely be very small and close to 0V since the diode voltage remains approximately constant after reaching the forward-biased conducting state.

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User EAMann
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if the diode voltage is around 0.7 V for the initial current of 0.1 mA, and it's around 0.8 V for the final current of 10 mA, you could estimate the change as
\( \Delta V \approx 0.8 \, \text{V} - 0.7 \, \text{V} = 0.1 \, \text{V} \).

To find the change in diode voltage
(\( \Delta V \)) when the current changes, you'll need additional information about the diode characteristics, such as its forward voltage drop or voltage-current relationship.

Assuming a simple linear model where the diode voltage ( V ) is directly proportional to the current ( I ), you can use Ohm's Law:


\[ V = I \cdot R \]

Here, R would be the resistance associated with the diode under the given conditions.

The change in diode voltage is then given by:


\[ \Delta V = V_{\text{final}} - V_{\text{initial}} \]

If the current changes from \
I_{\text{initial}} \) to \( I_{\text{final}} \), the change in diode voltage is:


\[ \Delta V = (I_{\text{final}} \cdot R) - (I_{\text{initial}} \cdot R) \]

The relationship between voltage and current in a diode is typically nonlinear. In the case of a semiconductor diode operating in forward bias, the relationship is often modeled using the Shockley diode equation:


\[ I = I_s \left( e^{(V)/(nV_T)} - 1 \right) \]

where:

I is the diode current,


\(I_s\) is the reverse saturation current,


\(V \)is the diode voltage,

n is the ideality factor (typically around 1 for silicon diodes),


\( V_T \) is the thermal voltage, and

e is the base of the natural logarithm.

Since this equation is nonlinear, finding the exact change in diode voltage
(\( \Delta V \)) when the current changes requires solving the equation iteratively or using numerical methods.

If you have access to the diode's datasheet or if it's a common diode like a silicon diode, you might find a voltage-current characteristic curve that provides a more accurate representation of the diode's behavior.

If the diode is well-behaved under the given conditions, you might be able to make an approximation. For instance, if the diode voltage is around 0.7 V for the initial current of 0.1 mA, and it's around 0.8 V for the final current of 10 mA, you could estimate the change as
\( \Delta V \approx 0.8 \, \text{V} - 0.7 \, \text{V} = 0.1 \, \text{V} \).

However, for precise calculations, especially with nonlinear components like diodes, it's essential to refer to the datasheet or detailed characteristics provided by the manufacturer.

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User Geoherna
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