Question

In: Physics

Each of two identical uniform metal bars has a resistance R. The end of one bar...

Each of two identical uniform metal bars has a resistance R.

The end of one bar is welded to the end of the other bar (Figure 1) . In terms of R, what is the resistance of this combination?

What is the resistance if the bars are welded together along their length? (Figure 2)

Solutions

Expert Solution

R = rho * L/A

If the end of one bar is welded to the end of the other bar,its length doubles.
Doubling the length will double the R.
so new resistance will be 2R

If the bars are welded together along their length, it area doubles. Doubling the area causes resisatnec to be halved.
So new resistance will be R/2


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