Question

13. A thin glass plate with the refractive index n has to surfaces which are not exactly parallel. In the interference image obtained in the reflected light under nearly nor- mal incident angles the distance between the dark stripes is found to be Ar. The wavelength is . Find the angle a between the plate surfaces. (1p) 14. Total internal reflection is observed in glass (n=1.5) and in water (n=1.33) at identical incidence angles. In which case the penetration depth of the refracted light in air will be larger? (1) 15. A thin lens made of glass (n = 1.5) has the focal length f in air. How the focal length will change if the lens is placed in quinoline (a liquid with high refractive index of Tg = 1.63)? (10) 16. An electric circuit contains a resistor R, a capacitor C and a solenoid with an induc- tance L connected serially. Near the solenoid one finds another one with an inductance L2, so that the mutual inductance between the solenoids is M. Find the resonance frequency in the circuit if the he ends of the second solenoid are directly connected. As- sume that the inductive reactance of the second solenoid notably exceeds its resistance. (1p)

Answer 1

(14 from Beer Lambert law, refracted light intensity - I- Io e-na, na refractive index, a= length nx = ln ( 1 ) - penetration depth * L % for the medium n is high or greater have less penetration depth. Heren 1.571.350, 21:33>24.5. So in water medium penetration depth will be longes.