How to calculate least count of ammeter

(I'm a student just like you so I might not be right) From what Sal said in an earlier video, the flow of electrons in a circuit is probabilistic. And current is the measure of how many electrons (charge) flows through a point per unit time (seconds). a path with high resistance would make the current flow through it much slower than a path with no resistance. So the current is lower for a high resistor because it lets fewer charge through it per second, not because the electrons intuitively "know" which path has least resistance. Electrons will go through every path, but lower resistance means some paths will let electrons through at a higher rate and therefore have a higher current Ah, but think about what would happen if this was true. If there are more electrons flowing into the resistor than flowing out of it (flowing electrons being what current is), then there would have to be a growing pile of electrons forming in the resistor. Since electrons are negatively charged and repel each other, this pile of electrons would quickly form a voltage greater than the one driving the current and stop it, or if the driving current was strong enough, cause the resistor to shoot out lightning. We don't see this, so we conclude that the current is the same before and after the resistor. This is one half of Kirchhoff's rules, which you can read about here for example: Hello Anusha, Before I answer your question consider the attributes of an ideal voltmeter and an ideal ammeter: The ...

Ammeter and voltmeter: • An ammeter is an instrument used to measure either alternating or direct current. • A voltmeter is an instrument that measures voltages of either direct or alternating current. Voltmeter and Ammeter. The lowest measurable value is known as the least count of an instrument. Least count of voltmeter: In the case of Voltmeter, we see 5 divisions = 2 volt. So least count (LC) = 2 5 = 0 . 4 V in this case as shown in the figure. Least count of ammeter: In the case of Ammeter, we see 5 divisions = 10 A m p e r e So least count (LC) = 10 5 = 2 A in this case as shown in the figure. Hence, the least count of ammeter is 2 A and of voltmeter is 0.4 V. Q. The following apparatus is available in the school laboratory: Battery : 4.5 V Rheostat : Varies battery voltage from 0 to 4.5 V Resistors : 1 Ω and 2 Ω Ammeters : A 1 of range 0 to 1 A; Least count 0.05 A : A 2 of range 0 to 3 A; Least count 0.1 A Voltmeters : V 1 of range 0 to 5 V; Least count 0.1 V : V 2 of range 0 to 10 V; Least count 0.5 V The best combination of ammeter and voltmeter for finding the resultant resistance of the two given resistors connected in series would be: (1) ammeter A 1 and voltmeter V 1 (2) ammeter A 1 and voltmeter V 1 (3) ammeter A 2 and voltmeter V 1 (4) ammeter A 2 and voltmeter V 2 Q. The science laboratory in a school has the following apparatus available in it: Battery : 6 V Rheostat : Varies battery voltage from 0 to 6 V Resistors : 3 Ω and 6 Ω Ammeters : A 1 of range 0 t...

We saw in our last tutorial that a permanent magnet moving-coil (PMMC) galvanometer is a type of instrument in which a current carrying coil is placed within a permanent magnetic field. When an electric current ( I ) passes through the coil, the electromagnetic field created around it reacts against the permanent magnetic field producing a deflecting torque that causes it to move. A pointer or needle attached to the coil indicates the amount of deflection, ( Φ ). We also learnt that permanent-magnet moving-coil meters can be converted into an effective Ammeters. As its names implies, an Ammeter is an instrument used for measuring electrical current (I) and gets its name from the fact that the unit of measurement is “amps”, or more precise, Amperes. But here lies the problem. As we saw in the previous tutorial about voltmeters, the full-scale deflection (FSD) of a standard PMMC meter is very small so they can carry only small currents, 0 to I FSD, given in micro-amperes (uA), or milli-amperes (mA) due mainly to the small wire size used in the windings of the PMMC moving coil. What if we wanted to measure a circuit current that is greater than this or up into the 10’s of amperes as a much higher current would force the meters pointer beyond its maximum FSD deflection which could potentially overheat or damage the coils windings, nevermind bend the pointer. So how can we use a standard PMMC meter to measure larger currents than those rated for FSD. To measure a circuit curren...

Table of Contents • • • • • • What is the least count of the ammeter? Find Least count of Ammeter and Voltmeter given below Ammeter Voltmeter For Ammeter, We see that 10 Divisions is equal to 0.2 Amperes So, Least Count = 0.2/10 = 0.02 A For Voltmeter, We see that 10 Division is equal to 1 Volt So, Least Count = 1/10 = 0.1 V What is the zero error of ammeter? Zero error: If the pointer of the ammeter or voltmeter is exactly at zero, when it is not connected to the circuit, then the instrument has zero error. If the pointer is above the zero mark, the the zero error is negative. The number of divisions it is above the zero mark are to be subtracted from the reading. What is meant by least count in an ammeter there are 20? For voltmeter, there are 20 divisions for a voltmeter between 0−0.5V marks. Means 0.5 volt is equal to 20 divisions. So, the range of voltmeter=0.5-0=0.5V. What is the least count of micro ammeter? Suppose the range of a given microammeter is between 0 to 400 mA, count the number of small divisions on the scale. If there are 40 divisions, then the least count of the microammeter is 400/40 = 10 mA. What is zero error and how we can find zero correction? If the zero on the circular scale is below the reference line then the error is positive. If the zero on the reference line is above the reference line then the error is negative. Zero correction can be done by adding the same number of the zero error but with the opposite sign. How is the least count of an ...

Table of Contents • • • • How do you calculate the LC of an ammeter? Least count of ammeter and voltmeter are? • =330=0.1A. • =0.520=0.025V. • Least Count=Value of one main scale divisionTotal number of scale division. What is meant by least count in a ammeter There are 20 divisions? (b) In a voltmeter there are 20 divisions between the ‘0’ mark and 0.5 V mark. (a) The minimum potential difference measured by a voltmeter between the two given terminals is called the least count of that voltmeter. What is the least count of measuring scale? In the simplest manner, we can define the least count of an instrument as the minimum value that we can measure from it. For example, the smallest distance that we can measure from a meter scale is 1mm, therefore the least count of meter scale is 1mm. What is ammeter used to measure? Ammeter, instrument for measuring either direct or alternating electric current, in amperes. An ammeter can measure a wide range of current values because at high values only a small portion of the current is directed through the meter mechanism; a shunt in parallel with the meter carries the major portion. Who invented multimeter? Donald Macadie In 1920, a British Post Office engineer, Donald Macadie, is credited with inventing the very first multimeter. The story goes that he was frustrated that he needed to carry a bunch of different tools when working on telecom lines, so he created one tool that could measure amperes, volts, and ohms. What is Vernier ca...

1. Connect Ammeter in series and voltmeter in parallel in an electrical circuit. Then Note down the readings in ammeter and voltmeter. 2.Least count is the smallest value that can be measured by the measuring instrument Least count Formula:= value measured in n divisions/n Least count of ammeter: The smallest value of current that can be measured For example:Let us calculate Least count of ammeter- 0-300mA Least count=range of ammeter divided by number of division Refer attachment 1:for ammeter picture Small divisions=30 suppose there are 30 division then, least count is =300/30=10mA Least count of Voltmeter: For example let us calculate least count of Voltmeter 0-15volts. Please refer to Attachment2 for voltmeter picture Main division 15 sundivision 30 least count=15/30 =1/2=0.5 Least count of this voltmeter is 0.5

Previous Years Papers • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • Examinations • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • Least Count The least count of an instrument is the smallest measurement that can be taken accurately with it. The least count of the metre scale is 1mm, and that of the ammeter is 2 ampere. Measurement of Length with a Metre Scale In daily life, the length is measured with the help of a metre scale. It is graduated in cm and mm, such that the value of one small division is 1 mm. Thus, a metre scale can be used to measure a length accurately up to 1 mm. Vernier Callipers Vernier callipers, instruments for making very accurate linear measurements, were introduced in 1631 by Pierre Vernier, a French mathematician. Vernier Calliper – Parts 1. Main Scale – The main scale is simil...

Table of Contents • • • • • • How do you determine the value of an ammeter? V=IR, here V is the potential difference across a resistance R through which a current I is flowing. The ammeter is connected in series with the circuit. So its reading will show the value of the current flowing in the circuit. Hence, the reading of the ammeter is equal to 1A. What is meant by least count in an ammeter there are? The least count of a measuring instrument is the smallest and accurate value in the measured quantity that can be resolved on the instrument’s scale. The least count is related to the precision of an instrument. Basically, An Ammeter has a range of 0−3A and there 30 divisions on the ammeter. What is least count of Screw gauge? The formula of least count of screw gauge is as follows: • Least count of screw gauge = (Pitch)/(number of divisions) • Least count of micrometer screw gauge = (1 mm)/(100) = 0.01 mm. What is ammeter reading? It is a instrument which helps in measuring ammeter the current in a circuit. By Ammeter reading we mean reading of the deflection of the magnetic needle which takes place because of the intensity of the magnetic field which takes place in the ammeter coil because of the amount of current flowing. What is range of an ammeter? An ammeter has a range of 0-3 ampere and there are 30 divisions on its scales. What is meant by least count? In the science of measurement, the least count of a measuring instrument is the smallest and accurate value in the...