Home 2nd Year Physics Notes Class 12 Physics Chapter 14 Notes – Electromagnetism

# Class 12 Physics Chapter 14 Notes – Electromagnetism

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In this post, I am sharing the Class 12 Physics Chapter 14 Notes PDF for the students of Intermediate Part 2. This chapter’s name is Electromagnetism. Students can download the Class 12 Physics Chapter 14 Notes PDF on their laptops or mobile. These Physics Notes are for all the boards working under the Punjab Board like Gujranwala Board, Lahore Board, Faisalabad Board, Multan Board, Rawalpindi Board, Sargodha Board, DG Kahn Board, and Sahiwal Board. Here are the complete FSC 2nd Year Physics Notes PDF chapters.

## FSC Part 2 Physics Chapter 14 Notes – Electromagnetism

Class 12 Physics Notes

### Electromagnetism

The branch of physics which deals with the study of magnetic fields due to the motion of charges.

### Describe the magnetic field due to current in a long straight wire.

Magnetic field due to current in a long straight wire

Take a straight, thick copper wire and pass it vertically through a hole in a horizontal piece of cardboard. Place small compass needles on arboard along a circle with the centre at the wire. All the compass needles will point in the direction of N-S. Now pass a way heavy current through the wire. It will be seen that the needles will rotate and will set themselves tangential to the circle. On reversing the direction of current, the direction of needles is also reversedl. As the current through the wire is stopped, all the needles again point along the N-S direction.

### What is the lamp and scale arrangement of a galvanometer?

#### Lamp and Scale Arrangement

In Sensitve galvanometer the angle of deflection is observed by means of small mirror attached to the coil along with a lamp and scale arrangement.

A beam of light from the lamp is directed towards the mirror of galvanometer. After reflection through the mirror it produces a spot on transclucent scale placed at a distance of 1m from galvanometer. When coil rotates, the mirror attached to the coil also rotates and spot of light moves along the scsle. The displacement of spot of light on scale is proportional to angle of deflection.

#### Pivoted type Galvanometer

In this type of galvanometer, the coil is pivoted between two jwelled bearings. The restoring torque is provided by two hair springs which also serves as current lead. A light aluminium pointer is attached to the coil which moves over the scale. It gives angle of deflection of the coil.