AS Level Physics: Resistance Help

  • Thread starter Thread starter CathyLou
  • Start date Start date
  • Tags Tags
    Resistance
Click For Summary

Homework Help Overview

The discussion revolves around a problem related to electrical resistance in the context of AS Level Physics. The original poster seeks assistance with calculating voltage drop in copper cables used as jump leads and understanding the practical reasons for using multiple strands of wire.

Discussion Character

  • Mixed

Approaches and Questions Raised

  • Participants discuss the relevant equation for resistance, considering factors such as length, cross-sectional area, and resistivity of copper. There is an indication that part (b) may involve practical considerations rather than purely theoretical physics.

Discussion Status

Some participants have begun to explore the calculations for part (a) while noting that part (b) may not strictly relate to physics principles but rather practical applications. There is an ongoing exploration of the implications of using multiple strands of wire.

Contextual Notes

Participants have noted that the stiffness of a single solid wire could be a factor in the discussion about using multiple strands, indicating a consideration of practical usability in the design of jump leads.

CathyLou
Messages
173
Reaction score
1
Hiya.

I'm currently studying AS Level Physics and I've no idea how to start the following question.

Any help would be really appreciated.

‘Jump leads’ may be used for starting the engine of one car using the battery of another car. One such set of leads is 4 m long, and consists of copper cables with a cross-sectional area of 13.6 mm^2.

(a) What is the voltage drop along the length of one of these cables when it is carrying a current of 100 A?

(b) In practice, such cables are made up of a number of strands of thin copper wire rather than a single strand of thicker wire. Why?

Thank you.

Cathy
 
Physics news on Phys.org
What equation for resistance? (Hint, length, cross-sectional area, and resistivity of copper are important)
 
After figuring out part a using drpizza's hint--part b has little to do with physics, it's a practical usage issue.
 
As for part b.

One solid 13.6 mm wire, is fairly stiff sooo
 

Similar threads

Resistance, current and current density
  • · Replies 8 ·
Replies
8
Views
2K
Platinum resistance thermometer and Kirchoff's Laws
  • · Replies 1 ·
Replies
1
Views
3K
2 Parallel connected cables resistance.Going from Diamater (mm) to m^2?
  • · Replies 7 ·
Replies
7
Views
3K
Coils arrangement so the hotplate operates at 3 diff. powers
  • · Replies 25 ·
Replies
25
Views
3K
Please help me calculate the wire temperature due to this current
  • · Replies 22 ·
Replies
22
Views
5K
Calculating Copper Wire Gauge for Resistance Thermometer Bridge Circuit
  • · Replies 6 ·
Replies
6
Views
2K
Induced Electric Field In Circuit With Varying Resistance
  • · Replies 3 ·
Replies
3
Views
2K
AC, 2 appliances in parallel, one of them is disconnected
  • · Replies 3 ·
Replies
3
Views
1K
Pls help me with my Resistivity Question in pHysics due tomorrow morning.
  • · Replies 1 ·
Replies
1
Views
2K
How do resistors handle high currents without burning up?
  • · Replies 11 ·
Replies
11
Views
3K