Can you give me a hint to find it correctly? From which formula should I start?PietKuip said:Your assumption that the currents (I1 and I2) are equal is not correct.
The power delivered to the load is maximal when the load resistor is equal to the internal resistance, so without calculation one can say that it is between 4 ohm and 9 ohm.
That is not correct: the power is zero at zero resistance (short circuit) and infinite resistance (open circuit).cnh1995 said:If you sketch the graph of power vs resistance, you'll see it is symmetrical on both the sides of the peak power.
r=6 ohm Thank you!cnh1995 said:If you want to go mathematically,
P=I2R will be helpful. Make proper substitution for I in terms of E and r.
Internal series resistance of a battery is the inherent resistance within the battery that affects its ability to deliver power. It is caused by the materials and construction of the battery and can decrease the voltage and current output of the battery.
Knowing the internal series resistance of a battery is important because it can affect the performance and lifespan of the battery. It can also impact the overall efficiency of a device or system that is powered by the battery.
The internal series resistance of a battery can be measured using a multimeter or a specialized battery tester. The battery must be disconnected from any external circuits and the voltage drop across a known load must be measured.
The internal series resistance of a battery can be affected by the type of battery, its age, temperature, and its level of charge. Higher temperatures can increase the resistance, while lower temperatures can decrease it. As a battery ages, its internal resistance may also increase.
The internal series resistance of a battery cannot be reduced, as it is a characteristic of the battery. However, choosing a battery with lower internal resistance or using multiple batteries in parallel can help to mitigate its effects on performance.