Alength of wire is cut into five equal pieces. the five pieces are then connected in parallel, with the resulting resistance being 2.00. what was the resistance of the original length of wired before it was cut?

The resistance is indirectly proportional to the current flowing in the wire. The resistance of the given full-length wire will be 50Ω.

Parallel resistance can be given as:

Where,

 - resulting resistance = 2Ω

In the given question, the wire was cut down into 5 pieces.

So,

Resistance in the series of full length wire,

So,

Put the value of

Therefore, the resistance of the given full-length wire will be 50Ω.

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The equivalent resistance of n resistors connected in parallel is given by
(1)

In our problem, the resulting resistance of the 5 pieces connected in parallel is , and since the 5 pieces are identical, their resistance R is identical, so we can rewrite (1) as

From which we find .

So, each piece of wire has a resistance of . Before the wire was cut, the five pieces were connected as they were in series. The equivalent resistance of a series of n resistors is given by

So if we apply it at our case, we have


therefore, the resistance of the original wire was .

45 is the correct answer

Since the pully is a simple machine so the mechanical advantage is a 1