Class name Subject Book title Chapter number Content Created at
Class XII Physics Physics Part-II 3 fall on the emitter plate of an evacuated glass tube enclosing two electrodes (metal plates), current flows in the circuit (Fig. 11.1). As soon as ...
Class XII Physics Physics Part-II 3 the material of the emitter plate. It was found that certain metals like zinc, cadmium, magnesium, etc., responded only to ultraviolet light, havin...
Class XII Physics Physics Part-II 3 of collector plate A with respect to the emitter plate C. The intensity and frequency of the incident light can be varied, as can the potential dif...
Class XII Physics Physics Part-II 3 It is found that the photoelectric current increases with increase in positive (accelerating) potential. At some stage, for a certain positive pote...
Class XII Physics Physics Part-II 3 observations (i), (ii) and (iii) given at the end ofsection 11.4.3. Further, we should note that in the wave picture, the absorption of energy by e...
Class XII Physics Physics Part-II 3 determined by the energy of each photon. Equation (11.2) is known as Einstein’s photoelectric equation. We now see how this equation accounts in a ...
Class XII Physics Physics Part-II 3 few years later and provided therefore, is the number of electrons coming out of a convincing evidence of the metal (for > ). This explains why, fo...
Class XII Physics Physics Part-II 3 Matter independent of the nature of the material. During 1906-1916, Millikan performedaseriesofexperimentsonphotoelectriceffect,aimedatdisproving E...
Class XII Physics Physics Part-II 3 electricity and on the photoelectric effect. We can summarise the photon picture of electromagnetic radiation as follows: (i) In interaction of rad...
Class XII Physics Physics Part-II 3 P 2.0×10 W3 M N = = −19 A E 3.98×10 J X 15 E = 5.0 10 photons per second. Example 11.2 The work function of caesium is 2.14 eV. Find (a) the thresh...
Class XII Physics Physics Part-II 3 For example, in the familiar phenomenon 8 of seeing an object by our eye, both descriptions are 1 – important. The gathering and focussing mechanis...
Class XII Physics Physics Part-II 3 relates the two attributes. Equation (11.5) for a material particle is basically a hypothesis whose validity can be tested only by experiment. Howe...
Class XII Physics Physics Part-II 3 For the ball: Mass m’ = 0.150 kg, speed v ’ = 30.0 m/s. Then momentum p’ = m’ v’ = 0.150 (kg) 30.0 (m/s) p’= 4.50 kg m/s de Broglie wavelength ’ = ...
Class XII Physics Physics Part-II 4 impact parameter, b of collision. The impact parameter is the perpendicular distance of the initial velocity vector of the a-particle from the cent...
Class XII Physics Physics Part-II 3 a helium-neon laser. The power emitted is 9.42 mW. (a) Find the energy and momentum of each photon in the light beam, (b) How many photons per seco...
Class XII Physics Physics Part-II 3 10 kg drifting with a speed of 2.2 m/s? 11.11 Show that the wavelength of electromagnetic radiation is equal to the de Broglie wavelength of its qu...
Class XII Physics Physics Part-II 4 Physics Chapter Twelve ATOMS 12.1 I NTRODUCTION By the nineteenth century, enough evidence had accumulated in favour of through gases carried out b...
Class XII Physics Physics Part-II 4 R internal structure of an atom and the spectrum of British physicist who did N radiation emitted by it. In 1885, Johann Jakob Balmer T (1825 – 189...
Class XII Physics Physics Part-II 4 atom as simple as hydrogen, consisting of a single electron and a single proton, emit a complex spectrum of specific wavelengths? In the classical ...
Class XII Physics Physics Part-II 4 of the radius of electron’s orbit to the radius of nucleus is (1010m)/(10 –15m) = 10 , that is, the radius of the electron’s orbit is 10 times larg...
Class XII Physics Physics Part-II 4 0 d 0 Thus the distance of closest approach d is given by 2Ze2 d = 4π ε0 The maximum kinetic –12rgy found in a-particles o9 natu2al 2rigin is 7.7 M...
Class XII Physics Physics Part-II 4 = 2 (12.3) 4πε0mv The kinetic energy (K) and electrostatic potential energy (U) of the electron in hydrogen atom are 1 2 e2 e2 K = mv = and U = − 2...
Class XII Physics Physics Part-II 4 specific wavelengths 296 only. A spectrum of this kind is termed as emission line spectrum and it Reprint 2026-27 Atoms consists of bright lines on...
Class XII Physics Physics Part-II 4 Niels Bohr studied in Rutherford’s laboratory for several months in 1912 and he was convinced about the validity of Rutherford nuclear model. Faced...
Class XII Physics Physics Part-II 4 initial and final states. The frequency of the emitted photon is then given by hν = E –iE f (12.6) where E aid E arf the energies of the initial an...