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

Imp, o meteors of rest-mass 0.1 and 0.2 kg, respectively, collide. If the r...

o meteors of rest-mass 0.1 and 0.2 kg, respectively, collide. If the relative speed before collision is 0.1c and an observer sees them coming with an equal and opposite speed and s

Find the x-component of the electric field, Presume that you are given an e...

Presume that you are given an expression for the electric potential V(x,y) as a function of x and y valid for points in the first quadrant of a Cartesian coordinate system and aske

Rotating biological contactor model, The topic for the project is to study ...

The topic for the project is to study and do calculation in Rotating Biological Contactor although you may choose a different title for your report. The aim is to research how the

#titleoptics.., a small object is 10cm in front of a plane mirror if you st...

a small object is 10cm in front of a plane mirror if you stand behind the object 30cm from it and look at its image for what distance must you focus your eyes

Screw gauge, screw gauge mostly based on what theory

screw gauge mostly based on what theory

Explain about intrinsic and extrinsic semiconductor, Q. Dissimilarity betwe...

Q. Dissimilarity between an intrinsic and extrinsic semiconductor? Answer:- Semiconductors permit only a little amount of light to pass through them. They are of two n-kin

Find the statement true or false and why, A bathtub is filled to the brim w...

A bathtub is filled to the brim with ice cold water and has an iceberg floating in it. It's a big bathtub the iceberg, of course, project above the surface of the tube when the ice

Motion in one dimension, an attacker at the base of a castle wall 3.65 m hi...

an attacker at the base of a castle wall 3.65 m high throws a rock straight up with speed 7.40 m/s at a height of 1.55 m above the ground. (a) will the rock reach the top of the wa

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