Current Electricity - Result Question 36

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38. You are given several identical resistances each of value $R=10 \Omega$ and each capable of carrying a maximum current of one ampere. It is required to make a suitable combination of these resistances of $5 \Omega$ which can carry a current of 4 ampere. The minimum number of resistances of the type $R$ that will be required for this job is

======= ####38. You are given several identical resistances each of value $R=10 \Omega$ and each capable of carrying a maximum current of one ampere. It is required to make a suitable combination of these resistances of $5 \Omega$ which can carry a current of 4 ampere. The minimum number of resistances of the type $R$ that will be required for this job is

3e0f7ab6f6a50373c3f2dbda6ca2533482a77bed:content/english/neet-pyq-chapterwise/physics/current-electricity/current-electricity—result-question-36.md (a) 4

(b) 10

(c) 8

(d) 20

[1990]

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Answer:

Correct Answer: 38. (c)

Solution:

  1. (c) To carry a current of 4 ampere, we need four paths, each carrying a current of one ampere. Let $r$ be the resistance of each path. These are connected in parallel. Hence, their equivalent resistance will be $r / 4$. According to the given

problem $\frac{r}{4}=5$ or $r=20 \Omega$.

For this propose two resistances should be connected. There are four such combinations. Hence, the total number of resistance $=4 \times 2=8$.