i got 1 terminal of a voltmeter close to the tv screen and earthed the other...it shows a max of .9 v.....that too when i move the needle on the TV screen.....if i keep it at 1 position....it ultimately becomes 0....got any reasons why??
2007-05-20 18:46:07 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Physics
The high voltage exists between the electron gun at the rear of the tube and the screen. The high voltage is at the back; the screen is at or close to ground potential. What you're reading is the static charge built up in the glass due to the electron bombardment on the inside. Leave the needle in one place and you bleed off the charge.
2007-05-20 20:12:31 · answer #1 · answered by injanier 7 · 0⤊ 0⤋
the reason why did the voltmeter show some reading on the surface of the screen is because of the static electric..
this is because inside the screen, electrons are shot from the rear end.. this shows up as colors on screen.. but it also charge up the screen with some static energy.
static energy can get charged until it can shock you, but it does not last long and does not have big impact to you..
2007-05-21 08:20:32 · answer #2 · answered by kish 2 · 0⤊ 0⤋
The voltage difference is between two parts INSIDE the TV. Electrons pass through this difference to be hurled at the screen. If there is a difference in potential between the screen and earth ground it is due to the collection of electrons on the screen, in which case Vscreen should be < Vearth.
2007-05-21 02:41:59 · answer #3 · answered by supastremph 6 · 0⤊ 0⤋
Hi. A CRT is a pretty good capacitor. Thermal changes can stress the glass and cause some high voltages, even if the tube was grounded yesterday. Be careful.
2007-05-21 01:51:33 · answer #4 · answered by Cirric 7 · 0⤊ 0⤋
Hello, a vacuum tube in which a hot cathode emits a beam of electrons that pass through a high voltage anode and are focused or deflected before hitting a phosphorescent screen.
i hope u got it.
2007-05-21 01:54:22 · answer #5 · answered by PG_13 5 · 0⤊ 0⤋