photoelectric effect dual nature of matter questions physics class 12 by vikas sir jee neet physics

What is photoelectric effect? State t he result of photoelectric effect experiment that could not be explained on the basis of laws of classical physics. Explain this effect on the b asis of quantum theory of electromagnetic radiations.

de Broglie proposed dual nature for electron by putting his famous equation lambda = (h)/(mv). Later on, Heisenberg proposed uncertainty principle as deltapDeltax ge (h)/(4pi). On the contrary, Particle nature of electron was established on the basis of photoelectric effect. When a photon strikes the metal surface it gives up its energy to the electron. Part of this energy (say W) is used by the electrons to escape from the metal and the remaining energy imparts kinetic energy (1//2 mv^(2)) to the ejected photoelectron. The potential applied on the surface to reduce the velocity of photoelectron to zero is known as stopping potential . When a beam of photons of a particular energy was incident on a surface of a particular pure metal having work function =(40 eV), some emitted photoelectrons had stopping potential equal to 22 V. some had 12V and rest had lower values. Calculate the wavelength of incident photons assuming that at least one photoelectron is ejected with maximum possible kinetic energy :

In a class of 55 students the number of students studying subjects are , 23 iin Mathematics 24.in physics 19in chemisty 12 in Mathematics and physics ,9 in Mathematics and chemistry ,7 in physics and chemistry and 4 in all the three subjects. the number of students who have taken ecactly one subject is

Asha's mother read an article in the newspaper about a disaster that took place at Chernobyl. She could not understand much from the article and asked a few questions from Ashs regarding the article . Asha tried to answer her mother's questions based on what she learnt in Class XII Physics. (a) What was the installation at Chernobyl where the disaster took place ? What according to you, wes the cause of this disaster? (b) Explain the process of release of energy in the intallation at Cheronbyl. (c) What, according to you, were the values displayed by Asha and her mother ?

Out of the three states of matter, only the gases have most of the physical properties common. They neither have definite shapes nor volumes. Upon mixing they form homogeneous mixture irrespective of their nature and can also be compressed on applying pressure. In addition to these, the gases obey different gas laws such as Boyle's Law, Charles's Law, Dalton's Law of partial pressures, Graham's Law of diffusion etc. Based upon these laws, ideal gas equation PV = nRT has been derived. For an ideal gas, number of moles per litre in terms of its pressure P, gas constant R and temperature T is :

Out of the three states of matter, only the gases have most of the physical properties common. They neither have definite shapes nor volumes. Upon mixing they form homogeneous mixture irrespective of their nature and can also be compressed on applying pressure. In addition to these, the gases obey different gas laws such as Boyle's Law, Charles's Law, Dalton's Law of partial pressures, Graham's Law of diffusion etc. Based upon these laws, ideal gas equation PV = nRT has been derived. Same mass of CH_(4) and H_(2) at taken in a container. The partial pressure caused by H_(2) is

Out of the three states of matter, only the gases have most of the physical properties common. They neither have definite shapes nor volumes. Upon mixing they form homogeneous mixture irrespective of their nature and can also be compressed on applying pressure. In addition to these, the gases obey different gas laws such as boyle's Law, Charles's Law, Dalton's Law of partial pressures, Graham's Law of diffusion etc. Based upon these laws, ideal gas equation PV = nRT has been derived. 4-4 g of a gas at STP occupies a volume of 2.224 L. The gas can be :

Out of the three states of matter, only the gases have most of the physical properties common. They neither have definite shapes nor volumes. Upon mixing they form homogeneous mixture irrespective of their nature and can also be compressed on applying pressure. In addition to these, the gases obey different gas laws such as Boyle's Law, Charles's Law, Dalton's Law of partial pressures, Graham's Law of diffusion etc. Based upon these laws, ideal gas equation PV = nRT has been derived. Which pair of gaseous species diffuse through a small jet with the same rate of diffusion at same P and T ?

Out of the three states of matter, only the gases have most of the physical properties common. They neither have definite shapes nor volumes. Upon mixing they form homogeneous mixture irrespective of their nature and can also be compressed on applying pressure. In addition to these, the gases obey different gas laws such as boyle's Law, Charles's Law, Dalton's Law of partial pressures, Graham's Law of diffusion etc. Based upon these laws, ideal gas equation PV = nRT has been derived. When the product of pressure and volume is plotted against pressure for a given amount of a gas, the obtained is

In a class of 55 students, the number of students studying different subjects are 23 in Mathematics, 24 in Physics, 19 in Chemistry, 12 in Mathematics and Physics, 9 in Mathematics and Chemistry, 7 in Physics and Chemistry and 4 in all the three subjects. Find the number of students who have taken exactly one subject.