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

What are links and symbolic links in unix file system, What are links and s...

What are links and symbolic links in UNIX file system? A link is a second name (not a file) for a file. Links can be used to allocate more than one name to a file, but cannot

Formation of stationary waves in stretched strings, Illustrate the formatio...

Illustrate the formation of stationary waves in stretched strings and thus deduce the laws of transverse waves in stretched string.

Evaluates in applying the biot-savart law, In calculating the integral that...

In calculating the integral that one evaluates in applying the Biot-Savart Law one is Answer: The Biot-Savart Law itself written in discrepancy form gives the infinitesimal

State kirchhoff rules of current distribution, State Kirchhoff's rules of c...

State Kirchhoff's rules of current distribution in an electrical network. Using these rules verify the value of the current in the electric circuit given below.

Determine the angle of the prism, A ray of light travelling in air is incid...

A ray of light travelling in air is incident on a prism and passes through it with a speed of 2X10 8 ms -1 parallel to its base. If the angle of refraction is similar to half of

Dc motor, #questionwhat is dc motor ..

#questionwhat is dc motor ..

Circular orbit at this height, One  scientist wants to put an 100kg experim...

One  scientist wants to put an 100kg experimental package in orbit around the Earth. The cost of deployment depends on the amount of more extra energy it takes to get it into the r

Lambert''s laws, Lambert's laws (J.H. Lambert): Lambert's first law ...

Lambert's laws (J.H. Lambert): Lambert's first law The illuminance on a surface illuminated through light falling onto it perpendicularly from a point source is propor

Antireflection films and interference filters, Q. What are antireflection f...

Q. What are antireflection films and interference filters?   Ans.   Anti reflecting Films: When a beam of light travels normally from a medium of refractive index µ2 to a me

Heat, a lead bullet moves horizontally with a velocity of 130ms and embedde...

a lead bullet moves horizontally with a velocity of 130ms and embedded into a cement wall after collision. if the specific heat capacity of lead = 130J/KgC and all heat produces is

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