The circuit shownin Fig. `7.33` contains a battery , a rheostat , and two identical lamps. What will happen to the brightness of the lamps if the resistance of the rheostat is increased? A. Less brighter BrighterB. Less brighter Loss brighterC. Brighter Less brighterD. No change Brighter

The circuit shownin Fig. `7.33` contains a battery , a rheostat , and

1.	The circuit shownin Fig. `7.33` contains a battery , a rheostat , and two identical lamps. What will happen to the brightness of the lamps if the resistance of the rheostat is increased? A. Less brighter BrighterB. Less brighter Loss brighterC. Brighter Less brighterD. No change Brighter
Answer» Correct Answer - A (a) Consider two extreme cases. (i) When the resistance of the rheostat is zero, the current through `Q` is zero since `Q` is short-circuited. The circuit is then essentially a battery in series with lamp `P`. (ii) When the resesitance of the rhostat is very large, amost no current flows throuh it. So, the currents through `P` and `Q` are almost equal. The current is essentially a battery in series with lamp `P` and `Q`

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The circuit shownin Fig. `7.33` contains a battery , a rheostat , and two identical lamps. What will happen to the brightness of the lamps if the resistance of the rheostat is increased? A. Less brighter BrighterB. Less brighter Loss brighterC. Brighter Less brighterD. No change Brighter

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