Potentiometer: Principle, Construction and Working of Potentiometer (Physics Animation)
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8 سال پیش
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This Physics e learning material helps you to understand the Principle, Construction and Working of Potentiometer. This educational content is prepared by the help of topmost physics teachers who have experience in online teaching.
The Potentiometer is an instrument used for the measurement of potential difference. It consists of a ten metre long uniform wire of manganin or constantan stretched in ten segments, each of one metre length. The segments are stretched parallel to each other on a horizontal wooden board. The ends of the wire are fixed to copper strips with binding screws. A metre scale is fixed on the board, parallel to the wire. Electrical contact with wires is established by pressing the jockey J.
A battery Bt is connected between the ends A and B of a potentiometer wire through a key K. A steady current I flows through the potentiometer wire. This forms the primary circuit. A primary cell is connected in series with the positive terminal A of the potentiometer, a galvanometer, high resistance and jockey. This forms the secondary circuit.
If the potential difference between A and J is equal to the emf of the cell, no current flows through the galvanometer. It shows zero deflection. AJ is called the balancing length. If the balancing length is l, the potential difference across AJ = Irl where r is the resistance per unit length of the potentiometer wire and I the current in the
primary circuit.
∴ E = Irl,
since I and r are constants, E α l
Hence emf of the cell is directly proportional to its balancing length. This is the principle of a potentiometer.
The Potentiometer is an instrument used for the measurement of potential difference. It consists of a ten metre long uniform wire of manganin or constantan stretched in ten segments, each of one metre length. The segments are stretched parallel to each other on a horizontal wooden board. The ends of the wire are fixed to copper strips with binding screws. A metre scale is fixed on the board, parallel to the wire. Electrical contact with wires is established by pressing the jockey J.
A battery Bt is connected between the ends A and B of a potentiometer wire through a key K. A steady current I flows through the potentiometer wire. This forms the primary circuit. A primary cell is connected in series with the positive terminal A of the potentiometer, a galvanometer, high resistance and jockey. This forms the secondary circuit.
If the potential difference between A and J is equal to the emf of the cell, no current flows through the galvanometer. It shows zero deflection. AJ is called the balancing length. If the balancing length is l, the potential difference across AJ = Irl where r is the resistance per unit length of the potentiometer wire and I the current in the
primary circuit.
∴ E = Irl,
since I and r are constants, E α l
Hence emf of the cell is directly proportional to its balancing length. This is the principle of a potentiometer.
8 سال پیش
در تاریخ 1395/05/28 منتشر شده
است.
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