Check your understanding!

1.The needle in the wheatstone bridge goes deflecting , what is your observation?
2.What is the result when ultrasonic waves are passed into a liquid medium and reflected?
3.What is the principle of physics used in finding the velocity and direction of moving particle in ocean deep?
5.4.What is your observation if a straight line is obtained in C display method with probes fixed on the heart?
6.If N1 is no. of atoms in ground state and N2 is no. of atoms in excited state , show that population inversion is essential for laser action?
7.In Einstein’s derivation of constants , explain how constants B12 is equal to B21?
8.In Nd:YAG laser, explain how laser emission is pulsed output?
9.In He-Ne laser, why the mixture of gases are in the ratio 10:1?
10.In a He-Ne laser emission, what is happening to 1.15 micron and 3.39 micron wavelength radiations emitted in the energy levels?
11.What are laser oscillations?
12.How light confinement is done in heterojunction semiconductor laser?
13.In a semiconductor what if Fermi level is found closer to valence band?
14.In a step index fibre , when a ray of light makes an angle of incidence equal to critical angle. Give your comments
15.How to reduce Rayleigh’s scattering?
16.What is experimental evidence to show the particle behavior of light?
17.What is the application of wave nature of electron?
18. Why a dome shaped LED is preferred over planar LED?
19. What is the result of recombination process in an indirect band gap semiconductor?
20. Bring out difference between LED and photodiode?
21. Why tapping a signal from an optical fibre is not possible?
22. Why a Diamond is an insulator while graphite a good conductor ,when the chemical content of both are same ,ie carbon?