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JEE Main202127 Aug 2021Morning ShiftPhysicsCurrent ElectricityActual

First, a set of n equal resistors of 10 Ω each are connected in series to a battery of E.M.F. 20 V and internal resistance 10 Ω . A current I is observed to flow. Then, the n resistors are connected in parallel to the same battery. It is observed that the current is increased 20 times, then the value of n is ___________.

Correct answer

0

Step-by-step solution

When the resistances of each 10   Ω â€‹ are connected in series and parallel then, R s = 10 n , and R p = 10 n . Given, i p = 20 i s , ⇒ 20 10 n + 10 = 20 20 10 n + 10 ⇒ 20 n 10 + 10 n = 20 20 10 n + 10 ⇒ n = 20 .

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