Question

Resistances R1 and R2 are connected respectively in the left gap and right gap of a metre bridge. If the balance point is located at 55 cm, the ratio R2/R1 is *​

Answer 1

Answer:

Balanced condition for 1st case:  

R  

2

​  

 

R  

1

​  

 

​  

=  

100−l

l

​  

=  

100−50

50

​  

=1

so R  

1

​  

=R  

2

​  

 

In 2nd case : when 24 Ω is connected in parallel to R  

2

​  

 , the resistance of R  

2

​  

 arm becomes R  

P

​  

=  

24+R  

2

​  

 

24R  

2

​  

 

​  

 

now balance condition is  

R  

P

​  

 

R  

1

​  

 

​  

=  

100−70

70

​  

 

or  

R  

P

​  

 

R  

1

​  

 

​  

=7/3

or R  

2

​  

=(7/3)R  

P

​  

    as R  

1

​  

=R  

2

​  

 

or R  

2

​  

=(7/3)  

24+R  

2

​  

 

24R  

2

​  

 

​  

 

or 24R  

2

​  

+R  

2

2

​  

=56R  

2

​  

 

or R  

2

2

​  

=32R  

2

​  

 

or R  

2

​  

=32Ω

Explanation:

Answer 2

Answer:

9/11

Explanation:

R1/R2 = L1/L2

= 55/45

= 11/9

R2/R1 = 9/11