Physics Questions

Materials that usually allow electricity to pass through them are called Good conductors of electricity.

Conductors conduct electrical current very easily because of their free electrons.

Examples are :: Aluminium, Gold, Copper, Silver

Materials that do not allow or oppose electrical current & make poor conductors are called Insulators.

Examples are :: Glass, Plastic, Wood, Air,...

In order of increasing penetration power, alpha particles have the lowest, then beta particles, then gamma rays.

Convex mirror is used as rear view mirror in vehicles. Because the image is smaller, more image can fit onto the mirror, so a convex mirror provides for a larger field of view than a plane mirror. This is why they are useful.

An electric arc is a visible plasma discharge between two electrodes that is caused by electrical current ionizing gasses in the air. Electric arcs occur in nature in the form of lightning.

Convection is by far the most efficient and common way for heat to be transferred through liquids and gases. It occurs when some regions of a fluid get hotter than others, causing currents in the fluid that move it around to distribute that heat more evenly.