第四章测试
1.The relationship between the Einstein coefficient of spontaneous radiation and the average lifetime τ of the excited state E2 is （ ）。
A:
B:
C:
D:
答案:B
2.The relationship between Einstein coefficients A21 and B21 is （ ）
A:
B:
C:
D:
答案:A
3.The longitudinal mode spacing of the resonant cavity is （ ）。
A:
B:
C:
D:
答案:B
4.The far-field divergence angle of the symmetric confocal cavity fundamental mode is （ ）。
A:
B:
C:
D:
答案:B
5.In the Witness system, random variables such as customer arrival intervals, service events, breakdown intervals, and repair times are generated by the random distribution function it provides. Correspond the standard distributions: normal, binomial, Poisson, negative exponential and applicable scenarios as （ ）.
A:number of faults occurring in a machine per month
B:Number of defective products in each batch
C:Time interval between failures
D:Machine processing time
答案:D
