EMF AND POTENTIAL DIFFERENCE
A BATTERY OF CELLS
A chemical reaction takes place within a cell to create a difference in electrical
potential difference between terminals of the cell
- A battery is a collection of cells
- Work done by battery = energy transferred to the charges
Emf – the total energy supplied per coulomb of charge by the battery
CELLS IN SERIES AND IN PARALLEL
POTENTIAL DIFFERENCE
Potential difference – the amount of work done per coulomb of charge moved
between two points
w
V= q
V = potential difference (V)
W = work done (J)
q = charge (C)
VOLTMETER
, Connected in parallel and measures potential difference
Does not affect current due to a very high resistance
EMF
The voltage measured across the terminals of a battery when no charge is
flowing through the battery
TERMINAL POTENTIAL DIFFERENCE
The voltage across the terminals of a battery when charge is flowing through
the battery
CURRENT
Current – the rate of flow of charge
q
I= t
I = current (A)
q = charge (C)
t = time (s)
CONVENTIONAL CURRENT
In metals electrons move from the negative terminal to the positive terminal.
This is electron flow
In electric circuits positive charge moves from the positive terminal to the
negative terminal. This is conventional current
AMMETER
Connected in series
Does not affect current due to a low resistance
RESISTANCE
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Danetucker. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $5.94. You're not tied to anything after your purchase.