Electric Energy Potential and Capacitors

Click For Summary
SUMMARY

The discussion focuses on calculating the constant current (I) that transfers a charge of 5 μC in 2 × 10−3 s, resulting in a solution of 2.5 mA. The relevant formula for this calculation is I = Q/t, where Q is the charge in coulombs and t is the time in seconds. The conversation also touches on the relationship between current and capacitors, specifically referencing the energy formula U = 1/2 QC, although the primary focus remains on understanding current in terms of charge and time.

PREREQUISITES
  • Understanding of electric charge and current (Coulombs and Amperes)
  • Familiarity with the formula I = Q/t for calculating current
  • Basic knowledge of capacitors and energy storage (U = 1/2 QC)
  • Concept of SI units and their significance in electrical calculations
NEXT STEPS
  • Study the relationship between charge, current, and time using I = Q/t
  • Explore the concept of capacitors and their energy storage capabilities
  • Learn about the significance of SI units in electrical engineering
  • Investigate practical applications of current calculations in circuit design
USEFUL FOR

Students preparing for exams in physics or electrical engineering, educators teaching concepts of electric current and capacitors, and anyone interested in understanding the fundamentals of electrical energy transfer.

neshepard
Messages
67
Reaction score
0

Homework Statement

So this is from a past test put up as a study guide, but I'm stumped here. The question is:

A spark jumps between two electrodes, transferring a charge of 5 μC in 2 × 10−3 s. The
constant current I that would transfer the same charge in the same time is

The Attempt at a Solution


The solution is 2.5e-3A.

What is the formula to use? Is this to be treated as a capacitor therefore U=1/2QC? Just need a nudge to get my head around it for the test Tuesday.

Thanks
 
Physics news on Phys.org
neshepard said:

Homework Statement

So this is from a past test put up as a study guide, but I'm stumped here. The question is:

A spark jumps between two electrodes, transferring a charge of 5 μC in 2 × 10−3 s. The
constant current I that would transfer the same charge in the same time is

The Attempt at a Solution


The solution is 2.5e-3A.

What is the formula to use? Is this to be treated as a capacitor therefore U=1/2QC? Just need a nudge to get my head around it for the test Tuesday.

Thanks

It is not a formula you need, it is contemplation of units.

Current is usually quoted in amperes, which means 1 Coulomb per second.
this spark involved much less that 1 Coulomb, but transferred in much less than a whole second. Think about it.

[Or use I = Q/t if you must]
 
Thanks. I can never remember the various SI units for things. I end up sticking to Amp, Volt, etc, and this seems to be the down fall of my understanding. But they just don't stick. Anyway, I know the time was fast, and would play a key part, but not where.

Cheers
 

Similar threads

  • · Replies 6 ·
Replies
6
Views
2K
Replies
4
Views
2K
Replies
5
Views
2K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 18 ·
Replies
18
Views
3K
Replies
8
Views
3K
  • · Replies 22 ·
Replies
22
Views
4K
  • · Replies 4 ·
Replies
4
Views
4K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K