A piece of wire having a resistance of 5 ohm is cut into
5 equal parts. If the 5 parts of the
connected in parallel, find the effective
of the combination
Answers
Considered a piece of wire having resistance 5 ohms, which is cut into 5 equal parts and is cut perpendicular to the length.
All five parts are connected in parallel.
We know that for Series resistance formula will be like Rs = R1 + R2 and for Parallel resistance formula will be like 1/Rp = 1/R1 + 1/R2
Now, given resistance is 5Ω and all are connected in parallel. Therefore, the resistance of the wire will be 5/R.
So,
1/Rp = 1/(R/5) + 1/(R/5) + 1/(R/5) + 1/(R/5) + 1/(R/5)
1/Rp = 5/R + 5/R + 5/R + 5/R + 5/R
1/Rp = (5 + 5 + 5 + 5 + 5)/R
1/Rp = 25/R
Rp= R/25 (Effective Resistance)
More Information
We know that,
R = p (l)/A
Here, The resistance of the conductor (wire) is directly proportional to the length of wire i.e. R ∝ l
Inversely proportional to the area of cross-section of wire i.e. R ∝ 1/A
R ∝ l/A
If we remove the sign of proportionality we use a constant i.e. p (rho).
........
QUESTION :
A piece of wire having a resistance of 5 ohm is cut into 5 equal parts.
If the 5 parts of the connected in parallel, find the effective resistance of the combination.
SOLUTION :
From the given Question, we can obtain the following information......
A piece of wire having a resistance of 5 ohm is cut into 5 equal parts.
The 5 parts of the connected in parallel.
Let the original resistance of the be wire be R.
We know that the resistance in a conductor is directly Proportional to it's length.
So,
Now, the resistance in each of the five pieces of the wire is equal to R / 5.
Now, these are connected in parallel.
So,
In Parallel connection
1 / R equivalent = 1 / R_{1} + 1 / R _ { 2 } +........
So,
In this case here -
1 / R _ { Equivalent } = ( 5 / R ) × 5
=> 1 / R _ { Equivalent } = { 25 / R }
=> R equivalent = R / 25
So the net effective resistance of the combination is R / 25.
ANSWER :
THE net effective resistance of the combination is R / 25.