Question

1.>For a Wheatstone bridge arrangement of four resistances – R1, R2, R3, R4 (Junction of Rj and R2>is connected to anode and Junction of R3 and Rg to the cathode of the cell). The null-point>condition is given by>a) (R1 - R3) = (R? - RA)>b) (R XR3) = (R2 X R:)>C)R1/R3=R2/R4>d) (R1 + R2) = (R2 + R)​

Answer 1

So,since the R1 ,R2 junction is connected to one end and R3 ,R4 junction is connected to other end  we can write the balanced condition as

$\frac{R1}{R2}$ = $\frac{R3}{R4}$

Which can also be written as

$\frac{R1}{R3} =\frac{R2}{R4}$

∴Option c will be the correct option.

Answer 2

From the given question the correct option is c.

As we know that the R1, R2 junction is connected to one end.

The R3, R4 junction is connected to another end.  

 

           $\frac{R^{1} }{R^{2} } = \frac{R^{3} }{R^{4} }$  

               or  

           $\frac{R^{1} }{R^{3} } = \frac{R^{2} }{R^{4} }$

So the null-point>condition is given by    $\frac{R^{1} }{R^{3} } = \frac{R^{2} }{R^{4} }$