JEE AdvancedPhysicsCurrent ElectricityNumerical+4 / −1
In order to measure the internal resistance r1 of a cell of emf E, a meter bridge of wire resistance R0 = 50 , a resistance R0/2, another cell of emf E/2 (internal resistance r) and a galvanometer G are used in a circuit, as shown in the figure. If the null point is found at l = 72 cm, then the value of r1 = . 
Numerical answer
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