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

How does laser printer works, How does laser printer works? When a text...

How does laser printer works? When a text or image is entered into the CPU, it makes a series of varying voltages. This controls a LED (light emitting diode) in the printer. Th

Resonance, give applications of resonance

give applications of resonance

What takes place when you travel across the dateline, Q. What takes place w...

Q. What takes place when you travel across the dateline? Answer:- If westbound the day modify to the next day. If eastbound the day is the day prior to. Appears strange bu

ELECREIC CIRCUITS AND ELECTRONICS, With the help of a circuit diagram, expl...

With the help of a circuit diagram, explain how regenerative feedback is provided in an Hartley oscillator?

Define average angular acceleration, It is significant to denote the time i...

It is significant to denote the time interval to in which we are talking about average. In a given time interval t 1 to t 2 the average angular acceleration is defined as ,

Relation between a proton and an alpha particle, A proton and an alpha part...

A proton and an alpha particle pass by the gap of a strong magnet.  If both particles have the similar initial velocity, how many times greater will the defection of the proto

Interference fringes, If a polarizer is placed in front of each slit, what ...

If a polarizer is placed in front of each slit, what modification be observed in the interference fringes. A) when the two polarizing axes are perpendicular? b) when the two

Polarisation, describe the construction and working of a Nicol prism.discus...

describe the construction and working of a Nicol prism.discuss how you obtain a plane polarised beam with it?

WEDGE CONSTRAINTS, HOW TO MARK DIRECTION OF ACCELERATION TO APPLY WEDGE C...

HOW TO MARK DIRECTION OF ACCELERATION TO APPLY WEDGE CONSTRAINTS ..

Liquid in Glass thermometer, Advantage and disadvantage of liquid in Glass ...

Advantage and disadvantage of liquid in Glass thermometer

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