Why ammeter should be connected in series

It is used to measure the current in ampere. To measure the current of a circuit, the ammeter is connected in series in the circuit so that the current to be measured must pass through it. Since, the resistance of ammeter is low, so its inclusion in series in the circuit does not change the resistance and hence the main current in the circuit. A voltmeter is a high resistance galvanometer.

It is used to measure potential difference between any two points of the circuit. To measure the potential difference between the two points of a circuit, the voltmeter is connected in parallel in the circuit.

The voltmeter resistance being high, it drawn minimum current from the main circuit and the potential difference to be measured is not affected materially. Recommend 0 Comment 0. Sukhmani Bhatia. A voltmeter has very high resistance and if it is connected in series then it would consume all the current and an ammeter has low resistance and if it is connected in parallel then all the current would flow through ammter and negligible in the circuit.

A voltmeter has high resistance and if it is connected in series then it would consume all the current but an ammeter has low reistance and if it is connected in parallel then all the current would flow through ammeter and nothing would flow in the circuit.

Related Wiki. Improve this question. Show 1 more comment. Active Oldest Votes. Improve this answer. John Rennie John Rennie k gold badges silver badges bronze badges.

And the ammeter's fuse could burn. Add a comment. Farcher Farcher Current means flow of charge free electrons in define direction.

Ammeter has very low resistance. So, Ammeter is always connected on series. Sarkar D. An Ammeter is a device used to measure the current flow through a conductor. The name is derived from the unit of current, Ampere.

This article explains why is ammeter connected in series but not in parallel. The flow of current is always along the length of the conductor. The purpose of using ammeter is to measure the rate of current flowing through it. The device is called a bridge because the galvanometer forms a bridge between two branches. A variety of bridge devicesare used to make null measurements in circuits.

Resistors R 1 and R 2 are precisely known, while the arrow through R 3 indicates that it is a variable resistance. The value of R 3 can be precisely read. With the unknown resistance Rx in the circuit, R 3 is adjusted until the galvanometer reads zero.

Wheatstone Bridge : The Wheatstone bridge is used to calculate unknown resistances. The variable resistance R3 is adjusted until the galvanometer reads zero with the switch closed. This simplifies the circuit, allowing Rx to be calculated based on the IR drops. The potential difference between points b and d is then zero, meaning that b and d are at the same potential. With no current running through the galvanometer, it has no effect on the rest of the circuit.

So the branches abc and adc are in parallel, and each branch has the full voltage of the source. Since b and d are at the same potential, the IR drop along ad must equal the IR drop along ab.

Again, since b and d are at the same potential, the IR drop along dc must equal the IR drop along bc. This equation is used to calculate the unknown resistance when current through the galvanometer is zero.

This method can be very accurate, but it is limited by two factors. First, it is not possible for the current through the galvanometer to be exactly zero. Second, there are always uncertainties in R 1 , R 2 , and R 3 , which contribute to the uncertainty in R x.

Privacy Policy. Skip to main content. Circuits and Direct Currents. Search for:. Voltmeters and Ammeters. Voltmeters and Ammeters Voltmeters and ammeters are used to measure voltage and current, respectively. Learning Objectives Compare circuit connection of an ammeter and a voltmeter. Key Takeaways Key Points A voltmeter is an instrument used for measuring electrical potential difference between two points in an electric circuit. An ammeter is a measuring device used to measure the electric current in a circuit.