Summary OCR A level Physics A 4.3 Electrical Circuits
3 views 0 purchase
Course
Module 4: Electrons, waves and photons
Institution
OCR
Summary notes for topic 4.3 Electrical circuits including Kirchhoff’s Second Law, series and parallel circuits, internal resistance, potential divider circuits, combining resistors, and sensing circuits. Notes include definitions, highlighted key terms, diagrams, explanations and break downs of e...
In
any circuit , the sum
of the electromotive forces is equal
to the sum
of the
potential differences around a closed
loop .
Series Circuits
•
Only have one path for the current .
Current is the same in
every position
• .
•
e.
m.f.io shared between components .
components with equal resistances equally share e. m.fi
•
•
components with
larger resistances take
up a
greater proportion
of e. m -
f .
When there than
is more one source of e. m
f. check
•
-
,
POLARITY E. = 9. or Ei " "
e. { e. m f. 3 OV
o
g.
=
-
.
- -
- -
- -
NOT 15 OV
-
.
Parallel circuits .
•
More than one possible path for charges .
•
Amount of charge on each path depends on resistance .
Greater the resistance of lower the current
branch
passing
•
,
through .
Each parallel branch can be
thought of as a separate
•
circuit .
Branches are independent .
, The sum of the p d s
of the components on
any branch
• -
-
to the total e.m.fi
is
equal
Combining resistors
In series :
total resistance is proportional to the number
of resistors therefore total resistance ,
is the sum of the individual resistances
RER ,
+
Rzt .
.
.
In
parallel : as more resistors are added in parallel , resistance
drops .
Additional resistor provides another
path
current cross-sectional
for ,
increasing area
,
and so
lowering resistance .
¥ ¥ ¥
=
+ . . _
Internal Resistance
This
Work is done in the
that some
cell whenever a current
lost
passes
not all
'
' through it .
as heat and
means
energy is ,
energy
transferred
to the
charge is available
for the circuit .
As result the terminals the power
a ,
p.cl .
measured
of at
source (terminal p
-
d.) is lower than the actual em f- This .
difference is called lost volts .
lowers the terminal p d.
Increasing the current .
,
as it means
by the charges
more work is done in the cell
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 hannahgrason. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $7.11. You're not tied to anything after your purchase.
