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Hi everyone.
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We have a question in which we have given that we have a wire which is having a resistance of 4 -oam and this is now stretched so that its length is become now three times of its initial length.
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So we need to find the final resistance.
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So in the question they have given the initial resistance.
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So initial resistance is given.
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So we can say that it is r and which is given in the question 4 -oam.
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So r is given 4 -oam.
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Now what we are doing, we are just stretching the wire to its three times.
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That means stretching wire to thrice its initial length, its original length.
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This we are doing.
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And so when we are doing this task, we need to find the new resistance.
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So we need to find the new resistance of the same wire.
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So how can we do this task? let us understand.
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Let's say r -ds is the new resistance.
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This we need to find so for finding the r d s we need to basically relate r d s and r so for this uh for for solving this question first we need to understand when we will stretch the wire to its area so uh original length of three times so what will going to be happen so let's suppose initial length and area initial length of wire is l initial length b l and area and area area b a.
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So we can say that this is the initial conditions.
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So when stretched, when stretched but we can say that we can say that the length is going to be three times.
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So if we will say the new length is l -des, so it will be three times of the initial length.
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And similarly if the area of cross -section is a -des, new area of cross -section is a -dice.
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So it will be a by three...