A wire has a resistance of 32 Q . It is melted and drawn into a wire of half of its original length. What is the resistance of the new wire?

examrobotsa's picture
Q: 28 (NDA-I/2008)
A wire has a resistance of 32 Q . It is melted and drawn into a wire of half of its original length. What is the resistance of the new wire?

question_subject: 

Science

question_exam: 

NDA-I

stats: 

0,2,11,4,7,2,0

keywords: 

{'resistance': [0, 0, 1, 2], 'wire': [0, 0, 7, 16], 'new wire': [0, 0, 1, 0], 'original length': [0, 0, 1, 0], 'half': [5, 2, 5, 2]}

In this question, we are given that a wire has a resistance of 32 Q. When it is melted and drawn into a wire of half its original length, we need to determine the resistance of the new wire.

Let`s analyze each option:

- Option 1, 32 Q: If the resistance of the new wire remains the same as the original wire, then the option is correct. However, when a wire is drawn into a smaller length, its resistance changes.

- Option 2, 16 Q: If the resistance is halved when the wire is drawn into half its original length, then the option may be correct. This is because the resistance of a wire is directly proportional to its length. But we need to confirm this.

- Option 3, 8 Q: This option suggests that the resistance of the new wire is one-fourth of the original resistance. This seems logical since the length is halved, so the resistance should also be halved twice. This is the correct answer.

- Option 4, 4 Q: If the resistance of the new wire is one-eighth of the original resistance, then this option may also be correct. However, this is not a logical possibility based on the scenario given.

Therefore, the correct