JAMB Physics Past Questions & Answers - Page 67

Conduction: the flow of internal energy from a region of higher temperature to lower temperature
Convection: heat transfer due to bulk movement of molecules within fluids
Expansion: the action of becoming larger or more extensive

Radiation refers to the transmission of energy as electromagnetic radiation from its emission at a heated surface to its absorption on another surface, a process requiring no medium to convey the energy.
Conduction is the transferring of heat by direct contact.
Convection is transferring heat through the motions of fluids (gases and liquids).

Y – Ray is a penetrating electro-magnetic radiation.
α – particle is produced in the process of alpha decay.
Neutron is a sub-atomic particle.

Thermonuclear fusion is the process that occurs when two atoms combine to make a larger atom, creating a whole lot of energy. Fusion already happens naturally in stars — including the sun — when intense pressure and heat fuse hydrogen atoms together, generating helium and energy.

Thermionic emission: thermally induced flow of charge
Nuclear fission: nuclear reaction or a radioactive decay process
Photoelectric emission: emission of electrons or other free carriers when light shines on a material

Brownian motion, also called Brownian movement, any of various physical phenomena in which some quantity is constantly undergoing small, random fluctuations.
If a number of particles subject to Brownian motion are present in a given medium and there is no preferred direction for the random oscillations, then over a period of time the particles will tend to be spread evenly throughout the medium.