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

Determine performance of program, In order to determine performance of prog...

In order to determine performance of program normal form of analysis of program is to just calculate total amount of CPU time needed to execute different part of program it implies

Henry, Henry; H (after W. Henry, 1775-1836): The derived SI unit of in...

Henry; H (after W. Henry, 1775-1836): The derived SI unit of inductance, described as the inductance of a closed circuit wherein an electromotive force of 1 V is generated whe

What is the principle of millikans oil drop method, Q. What is the principl...

Q. What is the principle of Millikan's oil drop method? Principle This method is foundation on the study of the motion of uncharged oil drop under free fall due to grav

Atom, what is an atom

what is an atom

State the conditions to achieve total internal reflection, Q. State the con...

Q. State the conditions to achieve total internal reflection. For entire internal reflection to take place (a) Light should travel from a denser medium to a rarer medium an

Can an electron be obtained from the nucleus, Can an electron be obtained (...

Can an electron be obtained (or come out) from the nucleus? Yes, electron having energy higher than the ordinary atomic electron might be come out of the nucleus because of be

Fringes in youngs double slit experiment, How does the distance between fri...

How does the distance between fringes in Young's double slit experiment change. a) If the colour of the light is changed from red to blue? b) If the slit separation is incre

Electric dipole, what should be the orientation of an electric dipole so th...

what should be the orientation of an electric dipole so that its potential enrgy is minimum

LOGIC, : Construct a regular proof to derive the conclusion of the followin...

: Construct a regular proof to derive the conclusion of the following argument: 1. (A & U) ~R 2. ~(~R v ~A) / ~U

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