1. Tardigrade
  2. Question
  3. Physics
  4. You are given several identical resistances each of value R=10 Ω and each capable of carrying a maximum current of one ampere. It is required to make a suitable combination of these resistances of 5 Ω 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

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. 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

AIPMTAIPMT 1990Current Electricity

Solution:

To carry a current of $4$ ampere, we need four path, 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 purpose two resistances should be connected.
There are four such combinations.
Hence, the total number of resistance $=4 \times 2=8$