Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: thegers91 on 03/01/2008 13:15:21

Title: Electrons!!
Post by: thegers91 on 03/01/2008 13:15:21

The power output of a TV screen is 24W. If the accelerating voltage is 12000V, calculate the number of electrons striking the screen per second?

Title: Electrons!!
Post by: lyner on 03/01/2008 14:32:46

Do you mean the power supplied to the electron gun is 24W?

Title: Electrons!!
Post by: lyner on 03/01/2008 14:49:50

The energy of each electron hitting the screen will be
12000 electron volts
= 1.60217646 × 10^-19 X 1.2x10^4
= 1.9x10^-15 J
If the beam power is 24W, the number of electrons per second is
24/1.9x10^-15
=1.26x10^16

Title: Electrons!!
Post by: Pumblechook on 03/01/2008 16:20:54

12 kV EHT  =  2 mA beam (Average?)  =  1.26×10e16 electrons

Amp is 6.24150948×10e18 Electrons/sec. 

Title: Electrons!!
Post by: lyner on 03/01/2008 18:11:15

Yes - I just like the electron volt. No need to work out the current.
You seem like a useful bloke with sums, Pumblechook- how about some profile?