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

Sound, experiments on how sound waves travel faster in iron

experiments on how sound waves travel faster in iron

Determine change in temperature - temperature, 9.8-g lead bullet with a muz...

9.8-g lead bullet with a muzzle velocity of 3.90 x 10 2 m/s is stopped by a wooden block. What is the change in temperature of the bullet if one-fourth of its original kinetic

Is light from object pass through the location of the image, In structuring...

In structuring the image does light from the object necessarily pass through the location of the image? Ans: No In reality in the case of a plane mirror (defining the obje

Explain density, Q. Explain density? Answer:- Density is a physica...

Q. Explain density? Answer:- Density is a physical characteristic also is a measure of mass per unit of volume of a material or substance. It is a dimension of the amount

Electromagnetic radiations, Electromagnetic radiations: What are the c...

Electromagnetic radiations: What are the common features among all the Electromagnetic radiations? Ans: 1. They all can be described in terms of oscillating electric and ma

Magnifying glass, Magnifying Glass: A biconvex lens of short focal leng...

Magnifying Glass: A biconvex lens of short focal length and low power which forms a virtual and magnified image of an object placed with its focal length is known as magnifying

Magnetism, explain origin of dimagnetsm on the basis of its atomic structur...

explain origin of dimagnetsm on the basis of its atomic structure

How is lasers use in medical treatment, How is lasers use in Medical Treatm...

How is lasers use in Medical Treatment? Lasers in Medical Treatment: Lasers used within cosmetic surgery as removing tattoos, stretch marks, scars, sunspots, birthmarks, wri

Electromagnetism, #quest. While music is on you will try to oppose the two ...

#quest. While music is on you will try to oppose the two ear phone pieces to attract.

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