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 is gas laws, What is Gas Laws? Kinetic theory states that the spee...

What is Gas Laws? Kinetic theory states that the speed of motion of the molecules in a substance decreases as the substance's temperature decreases. As well, the speed of motio

Aiming above the monkey- vectors and projectiles, Aiming Above the Monkey ...

Aiming Above the Monkey Assume a zookeeper must shoot a banana from banana cannon to a monkey who hangs from the limb of a tree. This particular monkey has a habit of dropping

Determine the potential difference across the ammeter, A current transforme...

A current transformer has two turns on the primary winding and a secondary winding of 260 turns. The secondary winding is connected to an ammeter with a resistance of 0.2.The

Communication physics, In a transmitter the final stage class C amplified ...

In a transmitter the final stage class C amplified with 18V DC supply calculate what equivalent Road the transistor to an antenna with 50ohm load impedance design and draw an L n

Component method, #question-the measurement of 30.43 degrees north of east....

#question-the measurement of 30.43 degrees north of east..

ACTIVITY, IN SUCCESSIVE DISINTEGRATION WHY DOUGHTER ELEMENT NOT DECAY WHEN ...

IN SUCCESSIVE DISINTEGRATION WHY DOUGHTER ELEMENT NOT DECAY WHEN IT FORM BUT DECAY AFTER A FIEW TIME FROM ITS FORMATION

Determine the combined stress distribution, A universal column of 6m carrie...

A universal column of 6m carries a Point Load of (180+n2) kN centrally at its axis. The column also carries one end of a simply supported beam of 5m with a uniformly distributed lo

Define the procedure to determine flaw by transducer, Define the procedure ...

Define the procedure to determine flaw by transducer. Procedure to find flaw: Cross section of typical contact transducer Ultrasonic flaw detection is fundamentally

Explain the resonance of sound in strings, Explain the Resonance of Sound i...

Explain the Resonance of Sound in Strings Strings on musical instruments, like harps, are held still at both ends, that is why the standing waves have nodes at every end of the

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