Question

7.
Assertion : When a wire is stretched to three times of its length its resistance becomes 9 times
Reason : Resistance of a given wire is directly proporational to length of wire
1
a) Both A and R are correct, but R is not the correct explanation of A
b) Both A and R are correct and R is the correct explanation of A
c) A is correct, but R is incorrect
d) R is correct, but A is incorrect​

Answer 1

Explanation:

When a wire is stretched to three times of its length its resistance becomes 9 times

Reason : Resistance of a given wire is directly proporational to length of wire

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Answer 2

In this question the correct answer is d
R=row l /A
Therefore l is directly proportional to resistance