Meterbridge (slide wire bridge)

  • Meter bridge is based on the principle of wheatstone bridge and it is used to find the resistance of an unknown conductor or to compare two unknown
  • Figure below shows a schematic diagram of a meter bridge

    Meterbridge (slide wire bridge)

  • In above figure AC is a 1m long wire made of maganin or constanan having uniform area of cross-section
  • This wire is stretched along a scale one a wooden base
  • Ends A and C of the wire are screwed to two L shaped copper strips as shown in figure
  • A resistance box R and an unknown resistance S are connected as shown in figure
  • One terminal of galvanometer is connected to point D and another terminal is joined to a jockey that can be slided on a bridge wire
  • when we adjust the suitable resistance of value R in the resistance box and slide this jockey along the wire then a balance point is obtained sat at point B
  • Since the circuit now is the same as that of wheatstone bridge ,so from the condition of balanced wheatstone bridge we have
    Here resistance P equals
    And Q=ρl2/A
    where ρ is the resistivity of the material of the wire and A is the area of cross-section of wire
    Now P/Q=(ρl1/A)(A/ρl2)=l1/l2

Latest Updates
Synthetic Fibres and Plastics Class 8 Practice questions

Class 8 science chapter 5 extra questions and Answers

Mass Calculator

3 Fraction calculator

Garbage in Garbage out Extra Questions7