Solving Resistors in Series: 1.50 V Battery

[franky1994]

Homework Statement

Three silver wires of equal length are connected in series with a 1.50 V battery. Their cross-sectional areas are 1.00, 5.00 and 10.0 cm2. (a) What is the potential difference across the narrowest wire? (b) The medium wire? (c) The widest wire?

Homework Equations

V= IR

1/Req = 1/R1 + 1/R2 + 1/R3 + … + 1/Rn

The Attempt at a Solution

Since the cross sectional area increases for each wire in the series, it can be assumed that the resistivity decreases from left to right or right to left (depending on how you draw your diagram).
That is:
R1 < R2 < R3.

I know the length of each wire is the same. However, I do not know the current. All the question provides me is the cross-sectional area of each wire.


Any help would be appreciated. (Also I will return the favor if I can. That depends on whether or not I have studied the problem you need assistance with.)

Thank you!

 

[barryj]

Your relevant equation is for parallel resistors.

 

[gneill]

Homework Statement

Three silver wires of equal length are connected in series with a 1.50 V battery. Their cross-sectional areas are 1.00, 5.00 and 10.0 cm2. (a) What is the potential difference across the narrowest wire? (b) The medium wire? (c) The widest wire?

Homework Equations

V= IR

1/Req = 1/R1 + 1/R2 + 1/R3 + … + 1/Rn

The Attempt at a Solution

Since the cross sectional area increases for each wire in the series, it can be assumed that the resistivity decreases from left to right or right to left (depending on how you draw your diagram).
That is:
R1 < R2 < R3.

I know the length of each wire is the same. However, I do not know the current. All the question provides me is the cross-sectional area of each wire.


Any help would be appreciated. (Also I will return the favor if I can. That depends on whether or not I have studied the problem you need assistance with.)

Thank you!

Hi franky1994, Welcome to Physics Forums.

While current, lengths, and resistivity of the metal are not supplied, you should be able to compare the resistances of the segments. Consider how the resistance of a wire varies with respect to length and cross sectional area. Hint: What happens if you arbitrarily assign a resistance of 1Ω to the first wire segment? What would the other resistances be?