Question

The resistance of 1m long nichrome wire is 6 ohm if we reduce the length of wire to 70 cm what is its resistance be?

Answer 1

Hello friend,

In this question the formula,
R= X*lenght /area of cross section
is used.
Where I've taken X as resistivity because I don't have the symbol 'rho'.

Placing the values given the question we get,

6 = X(1)/A ............(1)

If the lenght is changed into 70 cm or 0.7 m. Then the formula will be...

Y = X(0.7)/A ............(2)

where Y is the new resistance of this wire.

Now, divide the equation (1) and (2).
we get,

=> 6/Y = 1/0.7
=> Y = 4.2 ohm

So, the new resistance will be 4.2 ohm.

Hope you get it.
Please make it brainliest!!