The concept of resistance is most often used at characteristic of conductivity of electrical circuits or separate conductors. It depends only on material of the conductor and its geometrical sizes. Changing these parameters, it is possible to lower resistance of the conductor. It is possible to lower the general resistance of the site of a chain, using properties of parallel connection of conductors.
It is required to you
- - tools for cutting of a wire;
- - table of specific resistance;
- - additional resistance.
Instruction
1. Define substance of which the conductor is made. Find its specific resistance by means of the table. Lower resistance of the conductor, having made just the same conductor, only of substance which specific resistance is less. How much there will be less this size, in so many time resistance of the conductor will go down.
2. If there is such opportunity, reduce length of the conductor which is used in a chain. Resistance in direct ratio to length of the conductor. If to truncate the conductor in n of times, then resistance will go down in as much time.
3. Increase the cross-sectional area of the conductor. Establish the conductor with big cross section or connect several conductors in parallel in a bunch of wires. How much the cross-sectional area of the conductor will increase, in so many time resistance of the conductor will go down.
4. It is possible to combine these ways. For example, to lower resistance of the conductor by 16 times, we replace it with the conductor, specific resistance is twice less, we reduce twice its length, and cross-sectional area 4 times.
5. To reduce resistance on the site of a chain, attach to it in parallel one more resistance which size calculate. Consider that at parallel connection, resistance of the site of a chain is always less than smallest resistance which is in parallel branches. Calculate the necessary resistance which needs to be attached in parallel. For this purpose measure resistance of the site of a chain of R1. Determine that resistance which has to be on it – R. After that determine resistance of R2 which needs to be attached to R1 resistance in parallel. For this purpose find the work of resistance of R and R1 and divide into the difference of R1 and R (R2 = R • R1 / (R1 - R)). Consider that on a condition, R1 is always more than R.