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

Faraday law of induction, faraday law of induction(differential and integra...

faraday law of induction(differential and integral form)

Determine the same mass that of an electron, Which of the following has the...

Which of the following has the same mass as that of an electron: (1) Photon (2) Neutron (3) Positron (4) Proton Ans: Positron

Dielectric constant of the material filling the gap, a) How much charge sho...

a) How much charge should be placed on it to raise its potential to 10,000 V. b)  A parallel plate capacitor having plate area 100 cm 2 and separation 1.0 mm holds a charge of

Quantum physics, find the kinetic energy of a proton whose debroglie is 1fm...

find the kinetic energy of a proton whose debroglie is 1fm

Physica;lchemistry, what happens when a melt caontaining 1%ag with 99%pb

what happens when a melt caontaining 1%ag with 99%pb

Magnetic induction heating, what project can i make that includes induction...

what project can i make that includes induction heating

What happens if or electrical joint is loose, What occurs if electrical con...

What occurs if electrical connection or electrical joint is loose? Ans: Because of loose connection at joints resistance at that point will increase thereby the I²R loses ar

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