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

All about bernoulli, write bernoulli,s equation using pressure,energy,and h...

write bernoulli,s equation using pressure,energy,and heads.

What is the cheetah average acceleration, A cheetah can reach a top speed o...

A cheetah can reach a top speed of 27.8 m/s in 5.2 s. What is the cheetah's average acceleration?

Kirkwood gaps, Kirkwood gaps (Kirkwood): Gaps in the asteroid belt, ca...

Kirkwood gaps (Kirkwood): Gaps in the asteroid belt, caused through resonance effects from Jupiter. Identical gaps exist in Saturn's rings, because of the resonance effects of

De broglie wavelength, De Broglie wavelength (L. de Broglie; 1924) The ...

De Broglie wavelength (L. de Broglie; 1924) The prediction which particles also have wave characteristics, where the effective wavelength of an element would be inversely propo

Hookes law, Hookes Law Hooke's equation actually holds (to some extent)...

Hookes Law Hooke's equation actually holds (to some extent) in several other situations whereas an elastic body is deformed, like as wind blowing on a tall building, a musician

What is nuclear fusion, In nuclear fusion two or more than two lighter nucl...

In nuclear fusion two or more than two lighter nuclei join to form a single heavy nucleus. The volume of one molecule so formed is less than the sum of the masses of parent nuclei.

What are the wave fronts, Q. What are the wave fronts? Answer:- (Ph...

Q. What are the wave fronts? Answer:- (Physics) A wave front is an fantasy surface joining all points in space that are reached at the same instant by a wave propagating th

What is an illuminator, What is an illuminator? An illuminator, light g...

What is an illuminator? An illuminator, light generator or source is a box along with a lamp inside, pointing in the direction of an opening where fiber optics is secured. Obvi

Damping coefficient, what is the physical significance of damping coefficie...

what is the physical significance of damping coefficient?

Ski saga problem, Q. Ski Saga Problem? James Bond is skiing down a snow...

Q. Ski Saga Problem? James Bond is skiing down a snowy slope in an attempt to run off a hostile pursuer. Unfortunately the pursuer has a speed advantage since James is only abl

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