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when we take a magnet near a tv or computer screen. There is a effect on the screen. We look orange light on it. How can it possible. Does magnet also attract electricity?

when we take a magnet near a tv or computer screen. There is a effect on the screen. We look orange light on it. How can it possible. Does magnet also attract electricity?

Grade:12

2 Answers

Nirmal Singh.
askIITians Faculty 44 Points
10 years ago

This only works on old fashioned tv screens or computer monitors, so to understand why this happens we need to know how they work. Inside a television there is a big glass chamber which has had all the air sucked out to make a vacuum. At the back of this chamber is an electrical gun which fires electrons towards the back of the screen. The screen is covered with tiny lumps of phosphor, which glows when an electron hits it. If you cover the whole screen with one color of phosphor, you get a black and white tv.

To make a color tv screen, they put tiny spots of three different colors of phosphor on the screen in groups. Each group contains a spot of red, a spot of green and one of blue. Lighting these up in different combinations can make all the colours you see on your tv.

As electrons fly towards the screen, they can be moved using a magnetic field – this lets you aim the electrons at the right spot of phosphor and get the right colours in the right place.

When you put a magnet near the tv, it diverts the electrons away from where they should go, and so the wrong phosphor spots light up and you don’t get the right colours.

Sometimes, if you put a magnet near a tv for too long, you can make bits of it magnetic and so it will always distort the colours, thish is how the colours stay there.

Some tv’s have a degaussing coil inside them that re-sets the magnetism when you switch them on, so the colours go back to being correct.

Thanks & Regards,

Nirmal Singh

Askiitians Faculty

lokesh palingi
44 Points
10 years ago
some times if we put a magnet near a tv for oo long, u can make bits of it magnetic and so it will always distort the colours,thish is how the colours stey there.

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