Final answer:
To calculate the voltage across a resistor in a circuit with a non-ideal diode, subtract the voltage drop across the diode (usually around 0.7 V for a silicon diode) from the battery's voltage. Use Ohm's law to find the current if necessary.
Step-by-step explanation:
To determine the voltage across a resistor when a non-ideal diode is in the circuit, we consider the behavior of the diode as described. When a diode is forward biased and conducting, the voltage across it is approximately 0.7 V for a silicon diode.
Assuming the diode is forward biased in the scenario presented, the voltage drop across the diode is subtracted from the total voltage supplied by the battery.
Firstly, we apply Ohm's law (V = IR) to the resistor. In a circuit with a diode in series with a resistor, the current through both components is the same.
If the battery voltage is known and the voltage drop across the diode is approximately 0.7 V, we subtract this value from the battery voltage to find the remaining voltage that appears across the resistor.
For example, if the battery supplies 9 V, and the diode drop is 0.7 V, the voltage across the resistor would be 9 V - 0.7 V = 8.3 V.
The voltage across the resistor is therefore determined by calculating the overall voltage left after accounting for the diode's forward voltage drop.