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

Which one of the subsequent is true of electric potential, Question: W...

Question: Which one of the subsequent is true of electric potential but isn't true of an electric field? Answer: The electric field acquaintances a vector with empt

Evaluate the spring constant of the spring, A small ball with a mass of 60....

A small ball with a mass of 60.0 g is loaded into a spring gun, compressing the spring by 12.0 cm. When the trigger is pressed the ball emerges horizontally from the barrel ata hei

Explain the conservation of momentum, Explain the Conservation of Momentum ...

Explain the Conservation of Momentum In a collision, energy is not all time conserved, if not the collision is totally elastic  (all stored energy is turned into kinetic energy

What is the angle of refraction in the flint glass, A piece of flint glass ...

A piece of flint glass is lying on top of a container of water (see figure below). When a red beam of light in air is incident upon the flint glass at an angle of 28°. What i

Magnetic Effects of Electric Current., A spring is held vertically downward...

A spring is held vertically downward and a current is passed through it . Then the length of the spring : A . increases B. decreases C . does not change D the spring osc

What are the applications of electron microscopy in industry, What are the ...

What are the applications of electron microscopy in industry? Industrial applications of electron microscopy: a. High-resolution imaging and Forensics b. Particle detecti

Explain lsolectric precipitation, lsolectric  precipitation: At isoelectr...

lsolectric  precipitation: At isoelectric pH  you  already know,  a protein does not  have  any  net  charge. So, they easily aggregate and precipitate without denaturation becaus

Logic gates, Ask question contest light circuit diagram #Minimum 100 words ...

Ask question contest light circuit diagram #Minimum 100 words accepted#

Heat therapy - c- radiowave heating( diathermy), C- Radiowave Heating( Diat...

C- Radiowave Heating( Diathermy) Short wave diathermy utilized electromagnetic wave in radio range ( ~10m ) and microwave range (~ 12cm) .Short wave diathermy penetrate deep into

What are the safety terms to be inspected on battery, What are the safety t...

What are the safety terms to be inspected on battery? Ans: Safety terms to be checked on battery are full complements of battery box fixing bolts and its tightness, observat

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