Sage-Tips

Why meter bridge Cannot be used for measuring very high resistance?

metre bridge is not suitable for both very high/low resistances..and the reason is as follows… If we measure too high resistance and the meter deflection is too small, ie, currents are too low. For Too low and you get errors due to the resistance of the wire and the connections.

Why is Wheatstone bridge or meter bridge method considered unsuitable for the measurement of very low resistance?

Measuring very low resistances using the bridge can give erroneous results due to resistance offered by the wires, the devices like galvanometer, internal resistance of the cell and other elements in the circuit. So, the low resistances when measured using a Wheatstone’s condition will give unfavourable answers.

Why is Metre bridge method considered unsuitable?

Why is the meter bridge method considered unsuitable for the measurement of very low resistances? While measuring a vary low resistnace using meter bridge,all other resistances used should have low values in order to ensure sensitivity of the bridge. Due to it, the measurement will not be accurate.

What is the problem in measuring resistance by Wheatstone bridge?

The resistance of the bridge changes because of the self-heating which generates an error. The thermal emf cause serious trouble in the measurement of low-value resistance. The personal error occurs in the galvanometer by taking the reading or by finding the null point.

Can a metre bridge be used to measure very low or very high resistance?

So, Can you find very high resistance accurately with the help of a Metre bridge? No, the metre bridge becomes insensitive for very high and very low resistance. If too high resistance is measured then the deflection of the metre bridge will be very small.

Which error of metre bridge is removed when the known and unknown resistance are interchanged?

The error created due to this is called end error. To remove this the resistance box and the unknown resistance must be interchanged and then the mean reading must be taken.

What are the limitations of Wheatstone bridge?

The disadvantage of the Wheatstone bridge is that it is not so precise when it is used to measure large resistances. When the large resistances are to be measured, the results are mostly non-linear. Sometimes the value of the resistance degrades depending on the temperature and the EMF applied.

Why is Wheatstone bridge method considered?

Significance. The Wheatstone bridge illustrates the concept of a difference measurement, which can be extremely accurate. Variations on the Wheatstone bridge can be used to measure capacitance, inductance, impedance and other quantities, such as the amount of combustible gases in a sample, with an explosimeter.

Is metre bridge considered suitable for measuring very low resistance?

No, the metre bridge becomes insensitive for very high and very low resistance. If too high resistance is measured then the deflection of the metre bridge will be very small. This means that the currents are also too low.

Why is Wheatstone bridge more accurate?

A Wheatstone’s bridge is more accurate than the other methods of measuring resistance because the resistance is obtained using the null method and is based on Kirchoff’s law. If one or more of the four resistances are changed, the current through the galvanometer becomes zero.

Which bridge can be used to measure very low resistance?

Kelvin Bridge
The Kelvin Bridge is a variation of the Wheatstone bridge which enables low resistances to be measured.

Which error of meter bridge is removed when?

end error
The end error can be removed by repeating the experiment with different known and unknown resistances and taking the mean of the resistances determined.