Given below are examples of some potential energy functions in one dimension. The total energy of the particle is indicated by a cross on the ordinate axis. In each case, specify the regions, if any, in which the particle cannot be found for the given energy.

The potential energy of a certain particle is given by U = 30x^2 - 20 y^2 . Find the force acting on the particle.

Consider a one-dimensional motion of a particle with total energy E. There are four regions A, B, C and D in which the realtion beetween potential energy V, kinetic energy (K) and total energy E is as given ahead. Region A: V>E, Region B : V E, Region D : V > K State with reason in each case whetehr a article can be found in the given region or not.

The existence of negatively charged particle in an atom was shown by J.J. Thomson as a result of the studies of the passage of electricity through gases at extremely low pressure known as discharge tube experiments. When a high voltage of the order of 10,000 volts or more was impressed across the electrodes, some sort of invisible rays moved from the negative electrode to the positive electrode these rays are called as cathode rays. Cathode rays travel in straight path in absence of electrical and magnetic field . Cathode rays consist of material part and charged particles? Cathode rays produce X-rays and light is emitted when they strike on ZnS screen. Cathode rays penetrate through thin sheets of aluminium and other metals . They affect the photogenic plate and passes heating effect when they strike on metal foil. The raito of charge to mass i.e charge/mass is same for all the cathode rays irrespective of the gas used in the tube. The existence of positively charged particle in an atom was shown be E. Goldstein. He repeated the same discharge tube experiments by using a perforated cathode. It was observed that when a high potential difference was applied between the electrodes, not only cathode rays were produced but also a new type of rays were produced simultaneoulsy from anode moving towards cathode and passes through the holes or canal of the cathode. These termed as canal rays or anode rays. These rays travel in straight lines and consists of positively charged particles. These rays have kinetic energy and produces heating effect also. The e/m ratio of these rays is smaller than that of electrons. Unlike cathode rays, their e/m value is dependent upon the nature of the gas taken in the tube. These rays produced flashes of light on ZnS screen and can pass throughs thin metal foils. They can produce physical and chemical changes and are capable to produce ionisation in gases. Which is not true with respect to cathode rays?

Direction. In the follwing questions, a statement of assertion is followed by a statement of reason. While answering a question, you are required to choose the correct are out of the given four responses and mark it as (A). If both assertion and reason are true and reason is the correct explanation of the assertion, (B) if both assertion and reason are true but reason is not correct explanation of the assertion. (C) if asssertion is true, but reason if false, (D) if both assertion and reason are false Assertion : A proton and an alpha particle having the same kinetic energy are moving in ircular paths in a uniform magnetic field. the radii of the ciruclar paths will be equal Reasons: Any two charged particles having equal kinetic energies and entering a region of uniform magnetic field vecb in a direction perpendicualr to the vecb , will describe circular trajectories of equal radii.

For a hypothetical hydrogen like atom, the potential energy of the system is given by U(r)=(-Ke^(2))/(r^(3)) , where r is the distance between the two particles. If Bohr's model of quantization of angular momentum is applicable then velocity of particle is given by:

Enzymes are biocatalysts. They catalyse biochemical reactions. In general they reduce activation energy of reactions. Many physico-chemical processess are enzyme mediate. Some examples of enzyme mediated reactions are given below. Tick the wrong entry:

Given below is some famous number associated with electromagnetic radiations in different contexts in physics. State the part of the electromagnetic spectrum to which belongs. 1057 MHz (frequency of radiation arising from two close energy levels in hydrogen, known as Lamb shift).

Given below is some famous number associated with electromagnetic radiations in different contexts in physics. State the part of the electromagnetic spectrum to which this number belongs. 14.4 keV [energy of a particular transition in "^57Fe nucleus associated with a famous high resolution spectroscopic method (Mossbauer spectroscopy)].