Why is ordinary Wheatstone bridge not suitable for measuring low resistance?

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Why is ordinary Wheatstone bridge not suitable for measuring low resistance?

Low Resistance: Wheatstone Bridge can not be used to measure low resistance because then the wire resistance and lead resistance come into the picture and affect the result.

Can we use Wheatstone bridge to measure low resistance?

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. The Kelvin bridge was specially adapted from the Wheatstone bridge for measuring very low resistances.

Which bridge can be used to measure very low resistance?

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

Why is Metre bridge is considered unsuitable for the measurement of very low resistance?

The meter bridge is sensitive when the resistance of all four arms of the bridge are off the same order. It is so far moderate resistance only the meter bridge becomes insensitive for too high or too low values of resistances. For Too low and you get errors due to the resistance of the wire and the connections.

Why metre bridge is not suitable for?

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.

Can we determine very low or very high resistance using metre bridge?

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. This means that the currents are also too low.

Which is not use of Wheatstones meter bridge?

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.

Which stone bridge is used to measure resistance in the range of?

Explanation: Wheatstone bridge is the simplest form of bridge circuit. It is basically used for the measurement of medium resistances in the range of 1Ω to a few megaohms. Explanation: Wheatstone bridge is used to measure the d.c. resistance of various types of wires for controlling the quality of the wires.

What is the principle of metre bridge?

The meter bridge principle is based on the Wheatstone Bridge circuit which says that if at any point or length (of a wire), the ratio of two resistances (say R1 and R2) is equal to the ratio of another two resistances (say R3 and R4 where R4 is the unknown resistance), then there shall be no flow of current at that …

Can a Wheatstone bridge be used to measure low resistance?

Low Resistance: Wheatstone Bridge can not be used to measure low resistance because then the wire resistance and lead resistance come into the picture and affect the result. Suppose a low resistance is 1 ohm and lead resistance is 0.02 ohm and then it’s already 2% error.

Which is better Kelvin bridge or Wheatstone bridge?

However if you need accurate or precision measurements, you will go for Wheatstone bridge, or for low resistance , use Kelvin bridge. The Wheatstone bridge is still the best method for measuring very small resistances – like the resistance of a length of wire – which shows 0 resistance with even a hand-held ohmmeter.

What happens when the strain on a Wheatstone bridge is zero?

If the strain applied on a strain gauge is more, then the voltage difference across the meter terminals is more. If the strain is zero, then the bridge balances and meter shows zero reading. This is about the resistance measurement using a Wheatstone bridge for precise measurement.

How does null deflection work on a Wheatstone bridge?

The Wheatstone bridge works on the principle of null deflection, i.e. the ratio of their resistances are equal and no current flows through the circuit. When is the Wheatstone Bridge balanced? A Wheatstone bridge is said to be in a balanced condition when no current flows through the galvanometer.