Physics Definitions Grade 11
Geometrical optics
Light Ray: Lines that are perpendicular to the light’s wavefronts
Law of Reflection: The angle of incidence is equal to the angle of reflection
Speed of light: Is constant in a given medium and has a maximum speed of
3,00x10*8 m.s in a vacuum
Refraction: Occurs at the boundary of two media. When light travels from one
medium to another, the speed of light changes but the frequency stays the
same
Refractive Index: The ratio of speed of light in a vacuum to its speed in a
given medium
Optical Density: The measure of refracting power of a medium
Critical Angle: The angle of incidence where the angle of refraction is 90°
Electric Circuits
Potential Difference: Work done per unit positive charge
Current: Rate of flow of charge
Resistance: A materials opposition to the flow of electric current
Ohms Law: Current flowing through a conductor is directly proportional to the
potential difference across the conductor at constant temperature
Power: Rate of electrical energy conversion in a circuit
Electrostatics
Coulomb’s law: 2 point charges in free air exert forces on each other. The
forces are directly proportional to the product of the charges and inversely
proportional to the square distance between the charges
Electric field: A region in space where a charged object experiences an
electrostatic force
Electromagnetism
Magnetic Field: A region in space where magnetic objects experience a
magnetic force
Magnetic Flux Density: The representation and direction of a magnetic field
Magnetic Flux: For a loop of area (A) in the presence of a magnetic flux
density (B) that is uniform, the magnetic flux through the loop is = BAcosΘ
Faraday’s Law: The induced emf in a conductor is directly proportional to the
rate of change of magnetic flux
Geometrical optics
Light Ray: Lines that are perpendicular to the light’s wavefronts
Law of Reflection: The angle of incidence is equal to the angle of reflection
Speed of light: Is constant in a given medium and has a maximum speed of
3,00x10*8 m.s in a vacuum
Refraction: Occurs at the boundary of two media. When light travels from one
medium to another, the speed of light changes but the frequency stays the
same
Refractive Index: The ratio of speed of light in a vacuum to its speed in a
given medium
Optical Density: The measure of refracting power of a medium
Critical Angle: The angle of incidence where the angle of refraction is 90°
Electric Circuits
Potential Difference: Work done per unit positive charge
Current: Rate of flow of charge
Resistance: A materials opposition to the flow of electric current
Ohms Law: Current flowing through a conductor is directly proportional to the
potential difference across the conductor at constant temperature
Power: Rate of electrical energy conversion in a circuit
Electrostatics
Coulomb’s law: 2 point charges in free air exert forces on each other. The
forces are directly proportional to the product of the charges and inversely
proportional to the square distance between the charges
Electric field: A region in space where a charged object experiences an
electrostatic force
Electromagnetism
Magnetic Field: A region in space where magnetic objects experience a
magnetic force
Magnetic Flux Density: The representation and direction of a magnetic field
Magnetic Flux: For a loop of area (A) in the presence of a magnetic flux
density (B) that is uniform, the magnetic flux through the loop is = BAcosΘ
Faraday’s Law: The induced emf in a conductor is directly proportional to the
rate of change of magnetic flux
