Question

Q3- to register R1 and R2 are connected in the left gap and the right gap of the metre bridge and the null point is obtained at 20 cm from the left on inter interchanging the register in the to give the null point shift by?

Answer 1

P/Q=L1/100-L1

R1/R=20/100-20

R1/R=20/80

R1/R=1/4

So R1=R/4

Now the resistors are interchanged

R/R1=L1/100-L1

R1=R/4

4=L1/100-L1

L1=80 cm