Quarks inside protons and neutrons are thought to carry fractional charges`(+2/3e, -1/3e)`.Why do they not show up in Millikan's oil drop experiment?

An oil drop of 12 excess electrons is held stationary under a constant electric field of 2.55 xx 10^4 NC^- 1 in Millikan’s oil drop experiment. The density of the oil is 1.26 g cm^-3 . Estimate the radius of the drop. (g = 9.81 m s^-2, e = 1.60 xx 10^-19 C) .

Tritium is an isotope of hydrogen whose nucleus Triton contains 2 neutrons and 1 proton. Free neutron decay into p+bare+barv . If one of the neutrons in Triton decays. It would transform into He^3 nucleus. This does not happen. This is because.

An atom of element E contains 3 protons, 3 electrons and 4 neutrons : (e) What type of ion, cation or anion, will be formed by an atom of element E ? Why ?

Given f(x)={{:(3-[cot^(-1)((2x^3-3)/(x^2))], x >0) ,({x^2}cos(e^(1/x)) , x<0):} (where {} and [] denotes the fractional part and the integral part functions respectively). Then which of the following statements do/does not hold good?

A ship is fitted with three engines E_1,E_2 and E_3 . The engines function independently of each other with respective probabilities 1/2, 1/4, and 1/4 . For the ship to be operational at least two of its engines must function. Let X denote the event that the ship is operational and let X_1, X_2 and X_3 denote, respectively, the events that the engines E_1, E_2 and E_3 are function. Which of the following is/are true?

It is now believed that protons and neutrons (which constitute nuclei of ordinary matter) are themselves built out of more elementary units called quarks. A proton and a neutron consist of three quarks each. Two types of quarks, the so called ‘up’ quark (denoted by u) of charge + (2//3) e, and the ‘down’ quark (denoted by d) of charge (-1//3) e, together with electrons build up ordinary matter. (Quarks of other types have also been found which give rise to different unusual varieties of matter.) Suggest a possible quark composition of a proton and neutron.

An atom of element E contains 3 protons, 3 electrons and 4 neutrons : (c) Write the electronic configuration of the element E.

In 1959 Lyttleton and Bondi suggested that athe expansion of the Universe could be expalined if matter carried a net charge. Suppose that the Universe is made up of hydrogen atoms with a number density N, which is maintained a constant. Let the charge on the proton be: e_p = -(1+y)e , where e is the electronic charge. show that the velocity of expansion is proportional to the distance from the centre.

Deutron is a bound state of a nuetron and a proton with a binding energy B=2.2 MeV. A gamma-rays of energy E is aimed at a deuteron nucleus to try to break it into a (neutron+proton) such that the n and p move in the direction of the incident gamma-rays . If E=B, show that this cannot happen. Hence calculate how much bigger than B must E be for a such a process to happen.

An atom of element E contains 3 protons, 3 electrons and 4 neutrons : What could element E be