Question about voltage in a battery

  • Thread starter jaredvert
  • Start date
  • #1
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
 

Answers and Replies

  • #2
Drakkith
Staff Emeritus
Science Advisor
21,276
5,117
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
PhysicoRaj
Gold Member
509
40
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
2,042
311
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
PhysicoRaj
Gold Member
509
40
You mean the change in K.E between two successive collisions?
 
  • #6
2,042
311
You mean the change in K.E between two successive collisions?

Yes, I did mean that.
 

Related Threads on Question about voltage in a battery

  • Last Post
Replies
2
Views
1K
  • Last Post
Replies
5
Views
1K
Replies
50
Views
2K
  • Last Post
Replies
3
Views
767
  • Last Post
Replies
8
Views
853
Replies
4
Views
9K
Replies
10
Views
5K
  • Last Post
Replies
1
Views
1K
Replies
2
Views
5K
  • Last Post
Replies
9
Views
8K
Top