单色平行光垂直照射在薄膜上, 经上下两表面反射的两束光发生干涉,如图8.2.1所示,若薄膜的厚度为e , 且n1<n2> n3 , l1 为入射光在n1 中的波长,则两束光的光程差为 ( )
A. 2 n2 e
B. 2 n2 e-l1 / (2 n1)
C. 2 n2e-(1/2)n1l1
D. 2 n2e-(1/2)n2l1
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一束波长为 l 的单色光由空气垂直入射到折射率为n 的透明薄膜上, 透明薄膜放在空气中, 要使反射光得到干涉加强, 则薄膜最小的厚度为( )
A. l / 4
B. l / (4 n)
C. l / 2
D. l / (2 n)w
( )is power equipment.
A. battery
B. audio
C. wiper
D. starting system
()conveys the drive to the wheels . The main components are clutch , gearbox , driveshaft , final drive , and differential .
A. Brake system
B. Steering system
C. Transmission system
D. Suspension system
() controls the direction of the movement .
A. transmission system
B. suspension system
C. brake system
D. Steering system