In the circuit shown in figure the reading of ammeter is the same with both switches open as with both closed. Then find the resistance R. (ammeter is ideal)
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3 Answers
150600Ω
Akash Anand Good work..keep it upUpvote·0· Reply ·2013-07-08 06:05:51
229When both switches are closed the 50-ohm resistor
gets short. With both switches open, we can apply KVL to find the current I in the 100ohm resistor. With the switches closed, the 100ohm resistor and R will be in parallel.The potential difference across them is the same and we can express the current i1 in the 100 ohm in terms of the current I total flowing into the parallel branch whose resistance is R, and the resistance of the 100-ohm resistor. I depends on the equivalent resistance when both switch is closed, so we can express i1 = I in terms of R and solve for R.
- Akash Anand Good work