Calculating unknown resistances by wheatstone bidge, Physics

Assignment Help:

Calculating unknown resistances

The current through the galvanometer (G) - a very sensitive ammeter, is reduced to zero by adjusting R4.  The bridge is then said to be balanced.  When the bridge is balanced, the voltage at A is equal to the voltage at B and no current flows between A and B.

424_wheat stone bridge.png

 

Hence       VR1             =       VR2

          therefore   I1 ´ R1           =       I2 ´ R2 ------------- (1)  (by Ohm's law)

          Also           VR3             =       VR4

          therefore   I1 ´ R3        =       I2 ´ R4 ------------- (2)

 

 

Dividing (1) by (2) 1368_Calculating unknown resistances.png

 

Therefore the unknown resistor  R3  = 1887_Calculating unknown resistances1.png    (all known values)

In calculations it is possible for any of the four resistors to be unknown.  However, provided that the bridge is balanced, the theory remains the same and all that is required is to transpose the equation to find the unknown 

 


Related Discussions:- Calculating unknown resistances by wheatstone bidge

What is meant by the rest mass energy of an electron, What is meant by the ...

What is meant by the rest mass energy of an electron? According to the Einstein's Theory of Relativity, the mass of a body (say a particle) occurs on the energy and on the mom

Explain electroplating, It is a method of depositing a thin layer of one me...

It is a method of depositing a thin layer of one metal over one more metal by the method of electrolysis. The articles of cheap solids are coated with valuable metals like silver a

Standing wave in a closed organ pipe, Organ pipes are the musical instrumen...

Organ pipes are the musical instruments which are used for making musical sound by blowing air into the line. Longitudinal stationary pulses are created on account of superimpositi

Vlaue of universal gravitational constant was measured by, The value of G, ...

The value of G, the universal gravitational constant, was measured experimentally by: a) Newton b) Cavendish c) Copernicus d) Kepler Ans: The value of th

Explai layers of human eye, Human Eye: It is spherical in shape, diame...

Human Eye: It is spherical in shape, diameter about 2.5 cm, having of three layers. a) Sclera                               b) Choroid

Physical significance of curl of a vector function, Describe the physical s...

Describe the physical significance of curl of a vector function?

Rain bow, why the shape of rainbow is ark?

why the shape of rainbow is ark?

Magnetism, what is the magnetic field at a distance l from the centre of th...

what is the magnetic field at a distance l from the centre of the circle of radius r which carries a current i

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd