A galvanometer, having a resistance of50Ωgives a full scale deflection for a current of 0.05 A. the length in meter of a resistance wire of area of cross-section 2.97×10−2cm2that can be used to convert the galvanometer into an ammeter which can read a maximum of 5A current is : ( Specific resistance of the wire =5×10−7Ωm)
A
9
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
6
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
3
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
D
1.5
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution
The correct option is C 3 Given G=50Ω,ig=0.05Amp.,i=5A,A=2.97×10−2cm2 and ρ=5×10−7Ω−m By using iig=1+GS⇒S=G.ig(i−ig)⇒l=GigA(i−ig)ρon putting values l = 3 m.