Physics - Bits and Bobs Trivia Quiz

Answer: Its yield point

So if a string obeys Hooke's law, on a graph plotting extension against force, the gradient should pass through the origin and the gradient should be straight.
The gradient of this graph (force/extension) is known as the force constant. The higher the value for the force constant the stronger the material the spring is made from.

Answer: UV light

As frequency increases the waves can more easily penetrate matter. Gamma rays for example can easily pass through human skin and their ionising power can cause mutations within the body.
As well as being dangerous to humans, gamma rays can also help protect human lives, as they are used in sterilising medical equipment and in the targeting and destruction of cancerous cells.

Answer: Light from air to glass will refract towards the normal more than in air to water

This is because glass is denser than water.
Materials are all given a refractive index relative to air which has a value of one. A greater value suggests that more refraction will take place.
Glass has a refractive index of 1.5 and water 1.33.

Answer: Total internal reflection

This means that all of the light re-enters the dense core.
The critical angle is the angle of incidence which causes the refracted light ray to pass along the boundary of the change in media (i.e. 90 degrees to the normal line).
Total internal reflection is used in fibre optics.

Answer: Work function

The emission of photo-electrons depends on the frequency of the light which falls on the metal surface (higher frequency means more energy).

If photo-electrons can be emitted, the number emitted per second depends on the intensity of the light.

Answer: Electrons which fall to lower energy orbitals lose energy in the form of photons of light

In a fluorescent tube, there is an electrode at each end. Electrons are emitted by the cathode and these electrons collide with gaseous atoms in the tube, causing their electrons to become excited and so move to higher energy orbitals. The electrons then fall back down to their lower energy levels, losing their energy as light.
The energy required to move an electron from one orbital to another is called the excitation energy.

Answer: The nucleus of an atom is dense and positively charged

Some alpha particles passed through the thin gold leaf and were scattered at an angle, this showed Rutherford that a nucleus has a positive charge.
However, almost all of the alpha particles passed through the gold leaf, showing an atom is mainly space. This was the most famous find of the experiment. This experiment disproved the "plum pudding" model of the atom which existed before.

Rutherford did also say that an atom was mainly empty space, but this was not suggested by alpha particle deflection, but by the fact that most particles passed through the gold leaf without being deflected.

Answer: Annihilation

The energy of the photons emitted during annihilation is equal to the combined rest energy of the particle and its antiparticle.
The opposite of annihilation is pair production.

The energy given out in an annihilation reaction can be huge, as shown in the book "Angels and Demons".

Answer: W+ Boson

In "beta+ decay" a proton is converted into a neutron, also producing a positron and an electron neutrino.
In "electron capture" a proton and an electron are converted into a neutron and an electron neutrino.
In a "neutron neutrino collision" a neutron and an electron neutrino are converted into an electron and a proton.

Answer: 2

Protons are said to have a charge of +1. They are made up from 2 "up" quarks and one "down" quark.
Neutrons, having a neutral charge, are made up from one "up" quark and two "down" quarks.
A meson must me made of one quark and one antiquark.
Kaons, as well as having either one "up" or one "down" quark, must possess what is known as a "strange" quark.