pp26 - PHYSICS A World View Tuesday 26 April 2005 READ PRAC...

PHYSICS: A World View
Tuesday, 26 April 2005
READ
PRAC
HW
LAB
Ch 21: Q 34, 35, 36, 37, 42, 45

Time to evaluate
Greg’s teaching

•
Rank all the bulbs below for brightness.
Explain your reasoning.
A
C B
A>B=C
A gets all of the current
while B and C each get half
of total the current.
B and C share equally since each branch has
equal resistance.
Be the river

Rank the bulbs
•
Rank all the bulbs below for brightness.
Explain your reasoning. Batteries and bulbs
are all the same.
A
C B
F
E D
A=F>B=C=D=E Both circuits have the same
current. Which comes first does not matter.

•
Current favors the branch of least resistance.
C<D Less current will take
the left branch since it has
more resistance than the
right branch.
•
Which is brighter, C or D? Explain.
A
C
B
D
Ranking: A>D>B=C
Be the river

A
C
B
D
E
E>A=B>C=D
Be the river

Parallel paths:
1,000,000 Ω
1 Ω
The equivalent resistance is:
A) greater than 1,000,000 Ω
Β29 between 1 and 1,000,000
Ω
C) less than 1 Ω

Parallel paths:
1,000,000 Ω
1 Ω
The equivalent resistance is:
A) greater than 1,000,000 Ω
Β29 between 1 and 1,000,000
Ω
C) less than 1 Ω

Rank the Resistances
A
E
R
R

Rank the Resistances