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The balancing length for a cell is 560 cm in a potentiometer experiment. When an external resistance of 10 Omega is connected in parallel to the cell , the balancing length changes by 60 cm. If the internal resistance of the cell is (n)/(10) Omega the value of n is .... |
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Answer» 10 Let, `epsilon` is emf of battery and , is internal resistance and x is potential gradient.when onJy battery is connected, then `epsilon =560x ""` ....(1) After connecting resistance , `(epsilon XX 10)/(10 + r)` = (560x - 60) x = 500x ...(2) From equation (1) and (2) `(560 xx 10X)/(10 + r)= 500`x `therefore 56 = 50 + 5r` `therefore 6 = 5r` `therefore r = 1.2Omega` `therefore (n)/(10) = 1.2"" therefore n = 12 ` |
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