How does a moving coil galvanometer measure current?
Moving coil galvanometer is an electromagnetic device that can measure small values of current. It consists of permanent horseshoe magnets, coil, soft iron core, pivoted spring, non-metallic frame, scale, and pointer. Torque acts on a current carrying coil suspended in the uniform magnetic field.
How is the deflection of a galvanometer measured?
In a suspended coil galvanometer, the coil is suspended by a thin phosphor bronze strip and the deflection of the coil is measured by a lamp and a scale arrangement. A suspended coil galvanometer can measure currents of the order of 10 -9 A.
What makes the sensitivity of a galvanometer higher?
The sensitivity of a galvanometer is higher if the instrument shows larger deflection for a small value of current. Sensitivity is of two types, namely current sensitivity and voltage sensitivity. The deflection θ per unit current I is known as current sensitivity θ/I
What happens if you hit the stop pin on a galvanometer?
If somehow a heavy current happens to flow into the coil of the galvanometer, then due to very large deflection the pointer of the galvanometer may strike the ‘stop pin’ and be broken, or coil of the galvanometer may burn due to excessive heat produced.
How is the deflection of a galvanometer related to a voltmeter?
The galvanometer shows the deflection when an electric current is passed through the coil. The deflection is directly proportional to the current passed. A voltmeter is an instrument used for estimating the electrical potential difference between 2 points in an electric circuit. Series resistance required for conversion
Which is more sensitive a pivoted coil or a suspended coil galvanometer?
A pivoted-coil galvanometer is also a moving coil galvanometer. It is less sensitive than a suspended coil galvanometer but is more convenient and practical. It consists of a coil having a large number of turns of fine insulated copper wire wound on an aluminum frame.
Can a galvanometer be used as an ammeter?
Hence it is necessary that the resistance of the ammeter be very small as compared to other resistances in the circuit. A galvanometer cannot be used as an ammeter because it has appreciable resistance and it can measure only a limited current corresponding to the maximum deflection on its scale.