When a shunt of `4Omega` is attahced to a galvanometer, the deflection reduces to `(1)/(5)`th. If an additional shunt of `2Omega` is attached. What will be the deflection?

Options

A. `1/2`
B. `((1)/(3))^(rd)`
C. `((1)/(4))^(th)`
D. `((1)/(8.5))^(th)`

Answer

D

Explanation

Data
`(theta _(91))/(theta)=1/4 , S_(1) =3 Omega " "therefore G=?`
`Now (S_(1))/(S_(1)+G)=(theta_(91))/(theta)`
`therefore (3)/(3+G) =1/4 " "therefore G= 9Omega`
Now ` (theta_(g_(2)))/(theta) =?`
`if S_(2) =3` parallel `2= (3xx2)/(3+2) =6/5`
`therefore (theta_(g_(2)))/(theta)=(S_(2))/(S_(2)+G)=((6)/(5))/((6)/(5)+9)=((6)/(6))/((51)/(5))=(6)/(51) =(1)/(8.5)`