Here's what I didBvU said:Can I rephrase the problem statement as :
With a resistor R1 connected to a battery, the current is I1.
With a resistor R2 connected to a battery, the current is I2.
Find emf and the internal resistance.
Your equation requires brackets: ## I_i = emf / (R_i + r_{internal})##
So you have two equations with two unknowns: ## emf## and ##r_{internal}##. Can you write them down and post ?
And: the mentor will move this thread to introductory physics homework.
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V=IR and not I/R.prishila said:efm=I1/(R1+r)=I2/(R2+r)
You're right. i corrected itcnh1995 said:V=IR and not I/R.
Check the 3rd equation.prishila said:I1/I2=(R2+r)/(R1+r)
I1R1+I1r=R2I2+I2r
r(I1-I2)=R2I2+I1R1
Correctedcnh1995 said:Check the 3rd equation.
Looks correct!prishila said:Here's what I did
efm=I1*(R1+r)=I2*(R2+r)
I1*(R1+r)=I2*(R2+r)
I1/I2=(R2+r)/(R1+r)
I1R1+I1r=R2I2+I2r
r(I1-I2)=R2I2-I1R1
r=(R2I2-I1R1)/(I1-I2)
I replaced R with what I found and it results
efm=I1I2(R2-R1)/(I1-I2)
Did I find efm and r correctly?
Electromotive force (emf) is the potential difference between the positive and negative terminals of a battery or power source. It is essentially the driving force that pushes electrons through a circuit. Voltage, on the other hand, is the measure of electrical potential difference between two points in a circuit. While emf is the total potential difference in a circuit, voltage is the difference in potential between two specific points.
The emf of a battery can be measured using a voltmeter. The voltmeter is connected across the positive and negative terminals of the battery, and the reading on the voltmeter is the emf of the battery.
The emf of a battery can be influenced by various factors such as the type of battery, the materials used in the battery, the temperature, and the state of charge. For example, different types of batteries (e.g. alkaline, lead-acid, lithium-ion) will have different emf values due to their varying chemical compositions and internal workings.
The inner resistor of a battery can be calculated using Ohm's Law, which states that the resistance (R) of a circuit is equal to the voltage (V) divided by the current (I), or R = V/I. To calculate the inner resistor of a battery, the voltage and current of the circuit must be measured while the battery is in use, and then the equation can be used to solve for R.
Yes, the emf of a battery can change over time. As a battery discharges, its emf gradually decreases. This is because the chemical reactions within the battery are producing less energy as the reactants are used up. Factors such as temperature and age can also affect the emf of a battery.