JAMB - Physics (2000 - No. 29)
If the frequency of an emitted x-ray is 1.6 x 10\(^{16}\)Hz, the accelerating potential is?
[e = 1.6 x 10\(^{19}\)C, h = 6.63 x 10\(^{-34}\)Js]
[e = 1.6 x 10\(^{19}\)C, h = 6.63 x 10\(^{-34}\)Js]
6630.0V
663.0V
66.3V
6.6V
解释
Energy imparted by the accelerating system = e x V, where V is the accelerating potential; and this energy is equal to the energy of the X-ray, give by hf
e x V = hf
∴ V = hf/e
(6.63 x 10\(^{-34}\) x 1.6 x 10\(^{16}\))/1.6 x 10\(^{-19}\)
= 6.63 x 10 = 66.3V
e x V = hf
∴ V = hf/e
(6.63 x 10\(^{-34}\) x 1.6 x 10\(^{16}\))/1.6 x 10\(^{-19}\)
= 6.63 x 10 = 66.3V