Question

已知某金屬表面在波長(zhǎng)為λ和2λ的單色光照射時(shí),釋放出的光電子的最大初動(dòng)能分別為30 eV和10 eV.則能使此金屬表面產(chǎn)生光電效應(yīng)的入射光的極限波長(zhǎng)是多少?

Answer 1

4λ

解析:

本題考查光電效應(yīng)方程的應(yīng)用.

E ₁=h－W                                                                                                   (2分)

E ₂=h－W                                                                                                   (2分)

W=h                                                                                                           (2分)

由以上三式聯(lián)立解得  λ₀=4λ.                                                                       (3分)