The diagram shows a cell connected in series with an ammeter and three resistors (10 Ω, 20Ω, 30Ω). The circuit can be completed by a movable constant M. When M is connected to x, then ammeter reads 0.6 A. what is the ammeter reading when M is connected to y?

The current when it is connected to x is 0.6 A, so net resistance is 10 ohms so the cell voltage is 10 × 0.6 = 6 V.


Now when M is connected to y


the net resistance is sum of the resistance of 10 Ω and 20 Ω


Rnet=10+20=30 Ω


As we know by ohms law,


V=I R


Putting the values in the equation, we get


6 V= I× 30 Ω


I= = 0.2 A.


Thus, the reading of ammeter is 0.2 A.


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