Table of Contents
- 1 Why is high resistance used in potentiometer?
- 2 Why do we convert high resistance to galvanometer into voltmeter?
- 3 What is the role of high resistance R connected in series with the galvanometer?
- 4 Why must a high resistance are usually connected in series with an electrostatic voltmeter?
- 5 How the sensitivity of a potentiometer can be increased?
- 6 When a high resistance R is connected in series with a voltmeter of resistance?
- 7 Why do we use high resistance in galvanometer instead of potentiometer?
- 8 How does a potentiometer work?
Why is high resistance used in potentiometer?
High resistance is used in potentiometer since while measuring the EMF of a cell, it does not draw any current from the source of known EMF.
Why galvanometer is used in potentiometer?
Definition: The galvanometer is the device used for detecting the presence of small current and voltage or for measuring their magnitude. The galvanometer is mainly used in the bridges and potentiometer where they indicate the null deflection or zero current.
Why do we convert high resistance to galvanometer into voltmeter?
To convert a moving coil galvanometer to a voltmeter, we add a high series resistance, but why?. The high resistance causes most of the voltage to drop across it, leaving a small voltage drop across the galvanometer. This also ends up making the voltmeter have very high resistance.
What is the function of high resistance connected series with the galvanometer does it affect the balance point?
the high resistance with the galvanometer is just to limit the current through the galvanometer when the voltage across the galvanometer is high because the internal resistance of the galvanometer is very low for high PD it can burn . so we put high resistance to keep it safe . it doesn’t effect the balance point .
What is the role of high resistance R connected in series with the galvanometer?
We can construct ammeters using a galvanometer by attaching a high resistance in parallel to the galvanometer. The parallel combination ensures that all current flows through the galvanometer while the high resistance doesn’t allow current to pass through itself.
What is the role of high resistance R connected in series with galvanometer?
A galvanometer can be converted into a voltmeter by connecting a very high resistance in the series. A voltmeter is used to measure the potential difference whereas an ammeter is used to measure the electric current.
Why must a high resistance are usually connected in series with an electrostatic voltmeter?
The voltmeter is only there to measure the difference, i.e. the voltage, at two points. The load of course wants the maximum of current and hence the high resistance in the voltmeter, so that the current is not splited up and wasted unnecessarily on the voltmeter.
Why is a high resistance resistor connected in series with the potential coil?
Higher resistance give more accurate voltage reading, So, we connect many resistor in series so that resultant resistance across line should be high and no(very less) current should pass through it and all current should force to pass through current coil, this will lead accurate reading of current .
How the sensitivity of a potentiometer can be increased?
The sensitivity of the potentiometer can be increased by decreasing the potential gradient. i.e., by increasing the length of the potentiometer wire. Sensitivity of potentiometer can be increased by: Increasing the length of the potentiometer wire.
What is a high resistance galvanometer?
To make the resistance as high as possible a series resistance is connected to the Galvanometer to convert it to a voltmeter. It also serves the purpose of protecting the Galvanometer from damage due to high current.
When a high resistance R is connected in series with a voltmeter of resistance?
When a high resistance ‘R’ is connected in series with a volmeter of resistance ‘G’, the range of the volmeter increases 5times.
What resistance should be connected in series of galvanometer?
A shunt resistance should be connected in parallel to the galvanometer so as to keep its resistance low. Such low resistance galvanometer ( ammeter) is used in series with the circuit to measure the strength of current through the circuit.
Why do we use high resistance in galvanometer instead of potentiometer?
Because galvanometer is a sensitive device. It show a large deflection even for small currents. In potentiometer when it is not balanced,a large current flows through it which can damage the galvanometer. To avoid this situation, we use a high resistance in series with galvanometer so that less current will flow through it.
Can a galvanometer in series with infinite resistance?
>> A galvanometer in series wi… In the ideal condition, the voltmeter should have infinite resistance in order to prevent error in reading. However, this is not practically possible.
How does a potentiometer work?
A potentiometer is a device which works on the principal of balancing lengths that is it has a very few range of length of wires at which then whole circuit can be balanced. A very high resistance is connected in series first so a to a very minute current flow through the circuit.
What is the resistance of a 10A moving coil ammeter?
A moving coil ammeter requires a potential difference of 0.4V across it for full scale deflection. It has fixed shunt resistance of 0.01 ohm with a coil circuit resistance of R=1k ohm. The value of shunt required to give full scale deflection when the total current is 10A is equal to