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

Cadmium rods are provided in a nuclear reactor, Cadmium rods are provided i...

Cadmium rods are provided in a nuclear reactor. Why? Cadmium rods are given in nuclear reactors due to when we begin nuclear reactor then more energy is required for start the

Explain metallization, Metallization: It is the process of giving electric...

Metallization: It is the process of giving electrical connections among different parts of the circuit. Aluminium is commonly used. It has a high electrical conductivity and a low

#title.fraunhoffer diffraction., explain the maxima and minima in fraunhoff...

explain the maxima and minima in fraunhoffer difraction

Project, project of class12,,to demonstrate electrostatics shielding

project of class12,,to demonstrate electrostatics shielding

Name the communication in which the sign is a discrete, With that purpose w...

With that purpose was famous Davisson-Germer experiment with electrons performed? Name the type of communication in which the sign is a discrete and binary coded version of the

Are there many type of single ends in optics fiber, Are there many type of ...

Are there many type of single ends? Single ends can be no matter which from a simple cut with snips or a cutter to a sophisticated polished encapsulation. The actual method use

What is incorrect with the principal ray, Question: A person is putting...

Question: A person is putting effort to determine the characteristics of an image formed by a converging lens by means of a ray tracing diagram. The person has sketched one pri

Chronology protection conjecture, Chronology protection conjecture (S.W. Ha...

Chronology protection conjecture (S.W. Hawking) The concept that the formation of any closed timelike curve will be destroyed automatically trhough quantum fluctuations as soon

Differences in construction of MOSFET and JFET, Differences in Construction...

Differences in Construction of MOSFET and JFET An N-channel JFET is demonstrated in figure (a). It comprises a thin N-type silicon bar with two islands of P-type semiconductor

Find the discharge between the two tanks, Water is draining from tank A to ...

Water is draining from tank A to tank B. The elevation difference between the two tanks is 10 m. The pipe connecting the two tanks has a sudden-expansion section as shown. The cros

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