What is the principle of a moving coil galvanometer?
A moving coil galvanometer works on the principle that a current-carrying coil placed in a magnetic field, experiences a torque. The coil springs along with the radial field ensure the deflection to be proportional to the strength of the current.
What is the principle of moving coil galvanometer with the help of diagram explain its working?
The working of a moving coil galvanometer is based on the fact that when a current carrying coil is placed in a magnetic field, it experiences a torque. Working: Suppose that a coil PQRS is suspended freely in a magnetic field. Let B = strength of the magnetic field in which the coil is suspended.
What is the concept of galvanometer?
: an instrument for detecting or measuring a small electric current by movements of a magnetic needle or of a coil in a magnetic field.
What are the advantages of moving coil galvanometer?
The advantages of a moving coil galvanometer are as follows: -A moving coil galvanometer has very high sensitivity. -It has very high accuracy and flexibility. -It does not easily get affected by stray magnetic fields.
What is the basic principle of a moving coil galvanometer Class 12?
Hence the principle on which a moving coil galvanometer works can be stated as to when a current-carrying coil which is suspended freely in a magnetic field a torque acts upon the coil and due to this torque the coil rotates and the deflection of the coil is directly proportional to the current flowing through the coil …
Why is it that while using a moving coil galvanometer?
A galvanometer can be converted into a voltmeter of given range by connecting a high resistance of suitable value in series with it, so that most of the voltage applied drops across it, enabling the galvanometer to measure much larger required voltage.
What is a moving coil galvanometer explain its sensitivity in terms of current and voltage?
The sensitivity of a Moving Coil Galvanometer is the ratio of the change in deflection of the galvanometer to the change in current. Therefore we write, Sensitivity = dθ/di. If a galvanometer gives a larger deflection for a small current it is a sensitive galvanometer.
What is a galvanometer why it is used?
A galvanometer is an electromechanical measuring instrument for electric current. Early galvanometers were uncalibrated, but improved versions, called ammeters, were calibrated and could measure the flow of current more precisely. They were the first instruments used to detect and measure small amounts of current.
How does a galvanometer deflect?
When the magnet is moved away from the coil, the galvanometer shows deflection in the opposite direction indicating the direction of induced current in the reversed direction. The direction of deflection in a galvanometer is reversed if the direction of motion (or polarity of the magnet) is reversed.
What are the disadvantages of moving coil galvanometer?
The disadvantages of a moving coil galvanometer as below: -It can only measure direct current and not alternating current. -Frequently, errors can be seen due to mechanical stress. Now, the number of terms here is N=10, the length of coil is L=12 cm, breadth of the coil is b=8cm.
What are the advantages and disadvantages of moving coil?
Moving coil instruments consume quite less power. This is because the resistance of moving coil is small. In Moving coil meters the ratio of torque to weight is quite high and this reduces the errors due to friction. The scale of moving coil instrument is uniform.
Why mirror is used in moving coil galvanometer?
The mirror attached to the coil frame rotates together with it. This form of instrument can be more sensitive and accurate and it replaced the Kelvin’s galvanometer in most applications. The moving coil galvanometer is practically immune to ambient magnetic fields.
Moving Coil Galvanometer Principle A current-carrying coil when placed in an external magnetic field experiences magnetic torque. The angle through which the coil is deflected due to the effect of the magnetic torque is proportional to the magnitude of current in the coil. Moving Coil Galvanometer Construction And Diagram
Can a galvanometer be used to increase current sensitivity?
Solution: No. An increase in current sensitivity of a moving coil galvanometer may not necessarily result in an increase in voltage sensitivity. As the number of turns (length of the coil) is increased to increase the current sensitivity of the device, the resistance of the coil changes.
How does the moving coil meter experiment work?
This experiment shows that electric currents generate magnetic fields and it was first carried out by Danish physicist Hans Øersted in 1820. It’s the basic science behind moving-coil meters. Inside a meter, a tight coil of copper wire, wrapped round an iron core, is mounted in between the poles of a permanent magnet.
How is current carried in a moving coil?
When a current-carrying coil is suspended in a uniform magnetic field it is acted upon by a torque. Under the action of this torque, the coil rotates and the deflection in the coil in a moving coil galvanometer is directly proportional to the current flowing through the coil.
