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

Pulses, what exactly is pulse height analysis

what exactly is pulse height analysis

Experiment of measuring jar or graduate, A measuring jar or graduate Se...

A measuring jar or graduate Select several straight-sided glasses jars of assorted sizes. Olive bottles are very useful for the making of graduated cylinders. Paste a strip of

What is the path of the force exerted on the particle, A positively charged...

A positively charged particle is pitiful southward in a downward-directed uniform magnetic field. The magnetic force is the merely force if any acting on the particle. What is the

Explain loudness, Loudness: It is the characteristics of sound by a fai...

Loudness: It is the characteristics of sound by a faint sound can be distinguish by a loud sound is known as loudness.

Omega, ohm; Omega; O (after G. Ohm, 1787-1854): The derived SI unit of...

ohm; Omega; O (after G. Ohm, 1787-1854): The derived SI unit of electric resistance, described as the resistance among two points on a conductor while a constant potential dif

Corrosion, A iron rod on the surface of the beach and other iron rod into t...

A iron rod on the surface of the beach and other iron rod into the sea water which metal corrodes easily? Ans) An iron rod on the surface of teh seawater because in sea it contains

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

Construction and working of nicol prism, Briefly explain with principle, th...

Briefly explain with principle, the construction and working of Nicol prism. Why the angle of incidence on Nicol prism would be around 14 o .

silver, Silver   Symbol     Ag ...

Silver   Symbol     Ag Atomic weight 107.868  Atomic number   47 discovery

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