Internal resistance, emf UNCERTAINTIES

In summary, the conversation discusses calculating the EMF and internal resistance of cells using a graph and incorporating uncertainties in the calculations. The equations used are y = mx + c and Vo = -rI + ε, and the uncertainties for Vo and current measurements are ±0.10V and ±0.10A, respectively. The calculated values for internal resistance and EMF are 0.12 ohms and 2.1V, but the uncertainties for these values are not yet determined.
  • #1
ProgMetal
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Homework Statement


"From your graph, calculate the EMF and internal resistance of your cells. Include uncertainties in your calculations"

Now I know how to work out the emf and int. resistance, but I am just not sure about how to incorporate uncertainties.


Homework Equations


y = mx + c
Vo = -rI + ε

The Attempt at a Solution


Now the uncertainty for my Vo measurement is ±0.10V and current measurements is ±0.10A.
the equation of the line is y = -0.12x +2.1
so the Int. resistance is 0.12ohms and the emf is 2.1V, but what are the uncertainties on these values?
 
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  • #2
I know that uncertainties are represented by Δx and Δy but I am unsure how to incorporate this into the equations.
 

Related to Internal resistance, emf UNCERTAINTIES

1. What is internal resistance?

Internal resistance is the opposition to the flow of electric current within a battery or other source of electricity. It is caused by the resistance of the materials used to make the battery, as well as other factors such as temperature and age.

2. How is internal resistance measured?

Internal resistance is typically measured using an ohmmeter, which measures the resistance of a circuit. To measure internal resistance, the circuit is first broken and the voltage of the battery is measured. Then, a known resistance is added to the circuit and the voltage is measured again. The internal resistance can then be calculated using Ohm's Law.

3. What is emf?

Emf stands for electromotive force and is a measure of the energy per unit charge that is supplied by a source of electricity, such as a battery. It is the force that causes electrons to flow through a circuit.

4. What are some sources of uncertainty when measuring internal resistance and emf?

Some sources of uncertainty include variations in temperature, age and condition of the battery, and errors in measurement equipment. The resistance of the wires used in the circuit can also affect the accuracy of the measurements.

5. How can we reduce uncertainties when measuring internal resistance and emf?

To reduce uncertainties, it is important to use high-quality and properly calibrated measurement equipment. Keeping a constant temperature and using new batteries can also help reduce variations in measurements. Additionally, taking multiple measurements and calculating an average can help to reduce random errors.

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