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

Waves, how to standing waves formed in closed pipes

how to standing waves formed in closed pipes

Expermient of a metal ring stand and rings, A metal ring stand and rings ...

A metal ring stand and rings A useful ring stand and rings can be made from a flat curtain rod and the fixtures which clamp over electric bulbs to hold lamp shades. These are u

Why x-rays are not used in microscopes, Q. Why X-rays are not used in micro...

Q. Why X-rays are not used in microscopes? 1) The wavelength of X-rays is slighter than that of the visible light. 2) X-rays can't be focussed as visible radiations are foc

Describe newton''s first law, Each object continues to be in its state of u...

Each object continues to be in its state of uniform motion or of rest in a straight line unless completed by some external force to perform otherwise. Newton's first law is real

How lots cph is able keep the spin of photon, As we know photon's spin is o...

As we know photon's spin is one, how lots CPH (that have spin) is able keep the spin of photon? Answer; the photon spin like electron spin comes up of its properties and indepe

Source of the coordinate system in question, 3 . 50 nC of charge is consist...

3 . 50 nC of charge is consistently distributed in a solid Styrofoam ball of radius 2 . 00 cm cantered at x = 2 . 00 cm on the x-axis of a Cartesian coordinate system. -1 . 25 nC o

Evaluate frequency to shatter the glass, Evaluate frequency to shatter the ...

Evaluate frequency to shatter the glass with a resonant vibration? Standing-wave vibrations are set up in a crystal goblet with four nodes and four antinodes equally spaced arou

What is intensity-wavelength graph, At certain sharply explained wavelength...

At certain sharply explained wavelengths, the power of X-rays is very large as marked K alpha, K beta .... As shown in figure. These X-rays are called as property of X-rays. At oth

How much power is delivered by machine, A machine performs 8 Joules of work...

A machine performs 8 Joules of work in 2 seconds. How much power is delivered by this machine? Ans: The power is delivered by this machine is 4 watts.

Determine the axial and shear force, Determine the Shear Force in kN rounde...

Determine the Shear Force in kN rounded to 1 DP and Bending Moment in kN.m rounded to 1 DP at point C in the beam when the distance CB is P53 m. Then determine the axial force roun

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