[填空题]
Estimate the approximate maximum deflectz0y 68 ;2 vks +j7ccrwrig db(j9 rmb,+g5nqozion of thn8a0 e98emcwaea35mi0x+d c xe electron beam near the center of amaeac n5 9ciw 8803xd+0me xae TV screen due to the Earth’s $5.0\times10^{-5}\mathrm{~T}$ field. Assume the CRT screen is 22 cm from the electron gun, where the electrons are accelerated
(a) by 2.0 kV, mm(Round to the nearest integer)
(b) by 30 kV. Note that in color TV sets, the CRT beam must be directed accurately to within less than 1 mm in order to strike the correct phosphor. Because the Earth’s field is significant here, mu-metal shields are used to reduce the Earth’s field in the CRT. mm(Round to the nearest integer)
