# The resistance of the meter bridge AB is given figure is 4. With a cell of emf ε=0.5 V and rheostat resistance Rh= 2 the null point is obtained at some point J. When the cell is replaced by another one of emf ε= the same null point J is found for Rh=6 . The emf  is ; (a) 0.6 V (b) 0.5 V (c) 0.3 V (d) 0.4 V

## Question ID - 50312 :- The resistance of the meter bridge AB is given figure is 4. With a cell of emf ε=0.5 V and rheostat resistance Rh= 2 the null point is obtained at some point J. When the cell is replaced by another one of emf ε= the same null point J is found for Rh=6 . The emf  is ; (a) 0.6 V (b) 0.5 V (c) 0.3 V (d) 0.4 V

3537

Potential gradient with Rh =2 is ×=L=100cm

Let null point be at cm

Thus =0.5V=……(1)

Now with Rh = 6

and at null point

…...(2)

Dividing equation (1) by (2) we get

thus

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