A wire of length l has resistivity ๐. If the wire Is divided in two halves, then resistivity of each halve is:
Correct answer: B. ๐
- A. ๐/2
- B. ๐
- C. 2๐
- D. ๐/3
Explanation
When a wire is cut into two equal halves, the resistivity (๐) of the material from which the wire is made remains unchanged. Resistivity is an intrinsic property that depends on the material itself and its temperature. Therefore, regardless of the length of the wire, each half retains the same resistivity as the original wire. Thus, the correct answer is ๐. Option A (๐/2) is incorrect because resistivity does not decrease with the length of the wire. Option C (2๐) mistakenly suggests that cutting the wire increases the resistivity, which is not the case. Option D (๐/3) similarly misrepresents the concept, as resistivity remains constant for a given material.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? [email protected]
About Current Electricity
Steady current relates charge flow to potential difference, resistance and resistivity, including how temperature changes a conductor's resistance. Sources with internal resistance have terminal voltage below their emf when delivering current, and maximum power output occurs under a specific load condition rather than at zero resistance.
Practise Current Electricity
1,052 free Current Electricity MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Physics questions like this
Physics is on 16 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Current Electricity questions
For 0.5 Siemens of conductance, resistance will be:
A wire of uniform area of cross-section A', length 'L', and resistance R is cut into two equal parts. What will happen to the resistivity of each part?
The ohmmeter of a portable digital multi meter need:
Of the following, the copper conductor that has the least resistance must be:
A resistor has a resistance of 200 ohms. If a current of 0.5 amperes flows through it, what is the voltage drop across the resistor?
Ohm's law states that the current is directly proportional to _ and inversely proportional to _