Question about voltage in a battery

In summary, voltage is the difference in electric potential between two points, with a higher voltage indicating a larger difference. In a real circuit, a higher voltage battery will cause more current to flow and can put out more power than a lower voltage battery. This is because a higher voltage accelerates the electrons to higher velocities, resulting in more collisions and heat dissipation. However, the drift velocity is small compared to random electron movements, so the number of collisions does not change significantly. The amount of energy the electrons pick up between collisions does increase with higher voltage.
  • #1
jaredvert
61
0
Does say a 1.5 volt voltage in a battery mean the change in electric potential as one electron goes from the negative terminus to the positive terminus? Does a larger voltage battery simply mean more kinetic energy through the load (hence more friction/heat)? Or does it have to do with something else? Thanks
 
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  • #2
Voltage itself is the difference in electric potential between two points. A higher voltage means a larger difference between those two points. If we put a test charge at one of these points, the higher voltage will cause the test charge to accelerate faster and have more energy when it reaches the 2nd point.

In a real circuit, a battery at 3.0 volts will cause more current to flow than a 1.5 volt battery will, as long as the resistance of the circuit doesn't change. The 3.0 volt battery has the potential to put out more power than the 1.5 volt battery.

For example, if we have a circuit with a resistive load of 30 ohms, then the 1.5 volt battery will cause 50 milliamps of current to flow and the load will consume 75 milliwatts of power.

In the same circuit, the 3.0 volt battery will cause 100 milliamps of current to flow and the load will consume 300 milliwatts of power.
 
  • #3
jaredvert said:
Does a larger voltage battery simply mean more kinetic energy through the load (hence more friction/heat)?

As Drakkith said, more voltage accelerates the electrons to higher velocities (drift velocities to be precise), which means more collisions with the constituent particles and thus more heat dissipation.
 
  • #4
PhysicoRaj said:
As Drakkith said, more voltage accelerates the electrons to higher velocities (drift velocities to be precise), which means more collisions with the constituent particles and thus more heat dissipation.

Because the drift velocity is so small compared to the random movements of the electrons, the number of collisions doesn't change significantly. The amount of energy that the electrons pick up from the field between collisions does.
 
  • #5
You mean the change in K.E between two successive collisions?
 
  • #6
PhysicoRaj said:
You mean the change in K.E between two successive collisions?

Yes, I did mean that.
 

1. What is voltage in a battery?

Voltage in a battery is the measure of the electric potential difference between the positive and negative terminals of the battery. It is also known as the electromotive force (EMF) of the battery.

2. How is voltage measured in a battery?

Voltage in a battery is typically measured using a voltmeter, which is a device that measures the potential difference between two points in an electrical circuit. The voltage is usually expressed in volts (V) or millivolts (mV).

3. What determines the voltage of a battery?

The voltage of a battery is determined by the chemical reactions that take place within the battery. Different types of batteries have different chemical compositions and therefore, different voltages.

4. What is the typical voltage of a battery?

The typical voltage of a battery can vary depending on the type and size of the battery. For example, a standard AA alkaline battery has a voltage of 1.5V, while a car battery has a voltage of 12V. Lithium-ion batteries used in electronics can have voltages ranging from 3.6V to 3.7V.

5. How does voltage affect the performance of a battery?

The voltage of a battery is directly related to its energy capacity and determines how much power it can supply. Higher voltage batteries can provide more power, but they also tend to have a shorter lifespan. In contrast, lower voltage batteries may have a longer lifespan but cannot supply as much power.

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