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

Determine speed of the slider, The spring of constant k is un-stretched whe...

The spring of constant k is un-stretched when the slider of mass m pass position B as shown in the figure above.  If the slider is released from the position A, Determine: (i) S

Explain electrical field, Normal 0 false false false EN...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4 A positive charge or

How much time is required to raise the temperature, how much time is requir...

how much time is required to raise the temperature of the water from A family comes home from a long vacation with laundry to-do and showers to take. The water heater has been t

How to find out neutral point, How to find out neutral point ? What all thi...

How to find out neutral point ? What all things we require to equate or form a equation to find the neutral poind and how to do it?

Omega, ohm; Omega; O (after G. Ohm, 1787-1854): The derived SI unit of...

ohm; Omega; O (after G. Ohm, 1787-1854): The derived SI unit of electric resistance, described as the resistance among two points on a conductor while a constant potential dif

Explain electrical bell, Electrical Bell: 1.An electromagnet, which is ...

Electrical Bell: 1.An electromagnet, which is made by winding insulated copper wire on a soft iron core. 2.An armature which is soft iron strip with spring. 3.A soft iron

Find the temperature of the drink, (a) Two 40 g ice cubes are dropped into ...

(a) Two 40 g ice cubes are dropped into 220 g of water in a thermally insulated container. If the water was initially at25°C, and the ice came directly from a freezer at -15°C,what

Define conduction, Figure denotes a rod whose ends are in thermal contact w...

Figure denotes a rod whose ends are in thermal contact with a hot reservoir at temperature T1 and a cold reservoir at temperature T2.  The ends of the rod are covered with insulati

Net Torque, A 65g ball with a diameter of 3.1cm begins at rest and rolls do...

A 65g ball with a diameter of 3.1cm begins at rest and rolls down an incline. The angular acceleration of the ball is a constant 0.55rad/s2. ( I ball=(2/5)mr2 ) Calculate the net t

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